Improvements in scalp elasticity and hair properties following supplementation with low-molecular-weight porcine placental peptides (Placenderm®): A randomized, double-blind, placebo-controlled clinical trial

Improvements in scalp elasticity and hair properties following supplementation with low-molecular-weight porcine placental peptides (Placenderm®): A randomized, double-blind, placebo-controlled clinical trial | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Research Article Improvements in scalp elasticity and hair properties following supplementation with low-molecular-weight porcine placental peptides (Placenderm®): A randomized, double-blind, placebo-controlled clinical trial Yu-ri Gwon, A Reum Kim, Ji-Hae Lee, Jin Hee Shin, Hae Kwang Lee, and 5 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-8923782/v1 This work is licensed under a CC BY 4.0 License Status: Published Journal Publication published 21 Apr, 2026 Read the published version in International Journal of Peptide Research and Therapeutics → Version 1 posted 9 You are reading this latest preprint version Abstract The aging of scalp and hair is a complex biological process characterized by reduced biomechanical elasticity and degradation of follicular support structures, resulting in altered hair physical properties and appearance. However, clinical evidence for nutritional interventions targeting these aging markers remains limited. This study investigated the effects of hydrolyzed low-molecular-weight porcine placental peptides (Placenderm®) on scalp elasticity and the biophysical and visible aging-related characteristics of hair. In this 24-week, randomized, double-blind, placebo-controlled, parallel-group trial, 100 adults were assigned to receive either Placenderm® (500 mg/day) or a placebo. Scalp elasticity (ballistometry), hair physical properties (diameter and tensile strength), hair shaft morphology and roughness (SEM and ImageJ analysis), and hair luster (SAMBA system and expert visual assessment) were evaluated at baseline and week 24. Subjective satisfaction and safety parameters were also monitored. After 24 weeks, the Placenderm® group demonstrated statistically significant improvements in scalp elasticity, hair diameter, and tensile strength compared with the placebo group. Scanning electron microscopy (SEM) analysis revealed a significant reduction in hair surface roughness (Ra) in the intervention group, suggesting attenuation of cuticle damage and structural degradation. In addition, hair luster scores and subjective satisfaction were significantly higher in the intervention group. No serious adverse events were reported. Oral supplementation with Placenderm® significantly improved scalp elasticity and hair physical and microstructural characteristics. These findings suggest that Placenderm® is a safe and effective nutritional intervention for mitigating age-related changes in the scalp and hair. Low-molecular-weight porcine placental peptides Scalp elasticity Hair luster Hair tensile strength Hair roughness Figures Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Introduction The human scalp is a specialized integumentary structure characterized by a high density of terminal hair follicles embedded within a dense collagenous dermal extracellular matrix (ECM). Increasing evidence indicates that follicular integrity is not solely governed by epithelial stem cell activity but is critically dependent on the structural and biochemical properties of the surrounding dermal niche (Hardy 1992; Abreu and Marques 2021; Hsu et al. 2014). The perifollicular ECM provides mechanical support and regulatory cues necessary for homeostatic hair cycling; its remodeling or degradation has been implicated in follicular miniaturization and progressive hair thinning (Piccini et al. 2022; Pappelbaum et al. 2024). Under normal conditions, the scalp is partially protected from UV exposure by hair coverage and exhibits a thicker dermis compared to other anatomical sites. Each follicular unit typically produces two to three terminal hairs, contributing to the mechanical stability of the hair shaft and overall hair quality (Tosti and Schwartz 2021). The biological mechanisms underlying scalp aging largely parallel those of general skin aging and are characterized by reduced tissue flexibility and diminished elastic recoil. These degenerative transitions involve the flattening of the dermo-epidermal junction and the loss of rete ridges. Furthermore, aging accentuates the structural distinction between the papillary and reticular dermis, a phenomenon closely associated with collagen denaturation within the papillary dermal layer (Williams et al. 2021; Ralph 2021). In addition to providing structural support, the dermal collagen network contributes to biomechanical tension that is essential for optimal dermal papilla function and coordinated hair cycle regulation. These age-related changes, particularly the compositional remodeling of the ECM, not only weaken the structural support of hair follicles but also impair nutrient delivery via the perifollicular microvasculature. Specifically, senescence of the ECM surrounding the dermal papilla (DP)—the central regulator of hair growth—disrupts the follicular nutritional niche, adversely affecting hair cycle regulation and follicle size maintenance (Williams et al. 2020; Jang et al. 2023; Kligman 1988). Such molecular shifts are linked to follicular miniaturization, functional regression, and hair shaft thinning. Collectively, these changes compromise the integrity of the perifollicular dermal niche, which is critical for maintaining follicular competence and structural stability. When combined with androgenetic factors, these changes manifest as perifollicular fibrosis and inflammatory responses. Ultimately, these alterations affect hair density, diameter, and luster, thereby impacting manageability and appearance. This highlights the clinical necessity for interventions that address both the physiological and psychosocial aspects of hair health, as visible hair thinning often diminishes self-esteem and psychological well-being (Jeong et al. 2011; Trüeb et al. 2018). Porcine placenta extracts, obtained through enzymatic digestion or acid hydrolysis, contain a diverse array of bioactive constituents, including amino acids, peptides, and growth factors (Pogozhykh et al. 2018). Among these, low-molecular-weight porcine placenta peptides (Placenderm®) have been shown to exert antioxidant and anti-inflammatory effects, suppress matrix metalloproteinases (MMPs), and stimulate fibroblast activity to induce procollagen type I synthesis (Sim et al. 2024). Clinical evidence suggests that Placenderm® supplementation significantly improves skin hydration and elasticity in middle-aged and older adults (Nguyen et al. 2025). Furthermore, Placenderm® is reported to upregulate insulin-like growth factor-1 (IGF-1) and vascular endothelial growth factor (VEGF), potentially enhancing perifollicular angiogenesis. Through modulation of the Wnt/β-catenin signaling pathway, Placenderm® may contribute to the remodeling of the dermal microenvironment and the restoration of physiological function in miniaturized follicles (Lee et al. 2025). Based on this evidence, the present study aimed to evaluate whether oral supplementation with Placenderm® improves scalp elasticity and hair physical properties, potentially through modulation of the dermal ECM and follicular niche. To this end, a randomized clinical trial was conducted in adults with mild-to-moderate hair damage to quantitatively assess changes in scalp elasticity, hair thickness, and luster, while confirming the efficacy and safety of the intervention. Methods Study design This randomized, double-blind, placebo-controlled, parallel-group clinical trial was designed to evaluate the efficacy and safety of oral low-molecular-weight porcine placental peptides (Placenderm®) in adults (aged 19–60 years) with mild to moderate hair damage. The trial was conducted at a single clinical research center in the Republic of Korea. Following the screening of 107 candidates, 100 eligible participants meeting the predefined inclusion and exclusion criteria were enrolled. Participants were randomly assigned in a 1:1 ratio to receive either Placenderm® (500 mg/day) or a matching placebo for 24 weeks. Efficacy and safety assessments were performed at baseline and at Weeks 8, 16, and 24 (Fig. 1 a). The study was conducted in accordance with the ethical principles of the Declaration of Helsinki and the International Council for Harmonisation (ICH) Guidelines for Good Clinical Practice (GCP). The study protocol, informed consent forms, and all relevant documents were approved by the Institutional Review Board (IRB) of the study site. Written informed consent was obtained from all participants prior to enrollment. Participants Eligible participants were required to meet all of the following inclusion criteria: adults without diagnosed hair loss disorders who exhibited mild to moderate hair damage, defined by a hair luster score of ≤ 3 on a standardized visual assessment scale and a total hair damage score of < 18 (Marsh et al. 2015; Nagase 2019). During the study period, all physical and chemical hair treatments, including perming and dyeing, were prohibited, and participants were restricted to using only the provided standardized hair care products to minimize external confounding factors. Exclusion criteria included diagnosed hair loss disorders (e.g., androgenetic alopecia); chronic or infectious scalp diseases or generalized pruritus of psychiatric or neurological origin; nutritional deficiencies due to extreme dieting or gastrectomy; prior surgical hair restoration; and recent use of systemic corticosteroids, vasodilators, or diuretics within 1 month, or 5-α reductase inhibitors (dutasteride or finasteride) within 6 months prior to screening. Randomization, Blinding, and Intervention Participants were randomly assigned in a 1:1 ratio to either the Placenderm® or placebo group using a computer-generated block randomization scheme implemented with IBM SPSS Statistics (version 29.0). To ensure a robust double-blind design, the investigational product and placebo were manufactured to be identical in appearance, color, odor, and taste, rendering them indistinguishable (Table 1 ). The investigational product and placebo were supplied by Daehan Chemtech Co., Ltd. (Korea) and provided in blinded, coded kits to maintain strict allocation concealment. Neither the participants nor the investigators involved in outcome assessment were aware of group assignments until study completion and database lock. Throughout the 24-week intervention period, participants were instructed to consume the assigned product once daily at bedtime, in accordance with the predefined dosing regimen. Table 1 Composition of the Investigational and Placebo Products (%) Ingredient Active Group (Placenderm®) Control Group (Placebo) Placenderm® 50.00 - Maltodextrin - 50.00 Corn starch 3.00 3.00 Microcrystalline cellulose 26.26 26.26 Carboxymethylcellulose calcium 5.00 5.00 Isomalt 9.00 9.00 Magnesium stearate 1.00 1.00 Silicon dioxide 1.50 1.50 Hydroxypropyl methylcellulose 2.40 2.40 Proprietary blend 1.00 1.00 Titanium dioxide 0.60 0.60 Glycerin 0.24 0.24 Total 100.00 100.00 Placenderm® and placebo tablets were indistinguishable in appearance, composition (excipients), and administration protocol. Efficacy and Safety Evaluations All efficacy assessments were conducted after approximately 2 hours of acclimatization in a climate-controlled environment (temperature 22 ± 2°C, relative humidity 50 ± 5%). Scalp Elasticity Scalp elasticity was evaluated at the vertex using a Ballistometer (BLS780; Dia-Stron Ltd., UK). The vertex was anatomically defined as the intersection of a vertical line drawn from the midpoint between both ears and the central parting line of the forehead. The mean value of three consecutive measurements at the same site was used for analysis. Hair Physical Properties Hair shaft diameter was measured using the ASW 300 system (AramHuvis, Korea). Hair samples were collected from three scalp regions (left temporal, right temporal, and occipital), and the diameter of the proximal portion of the hair shaft was determined. Hair tensile strength was assessed using a universal testing machine (UNITEST M1; TESTONE Co., Ltd., Korea). Hair samples collected from the same regions were subjected to longitudinal tension until fracture, and the maximum load was recorded. Hair Surface Morphology and Roughness Hair shaft surface morphology was examined using scanning electron microscopy (SEM; EM-30, Coxem, Korea). SEM images were independently evaluated by three dermatologists using a validated 12-point hair damage grading scale (Lee et al. 2016). In addition, the mean arithmetic surface roughness (Rₐ) was quantitatively calculated from SEM images using ImageJ software (National Institutes of Health, USA). Hair Luster Hair luster was quantitatively evaluated using the SAMBA hair system (Bossa Nova Technologies, USA) by measuring reflected light intensity from randomly selected hair bundles. Additionally, standardized digital photographs (Canon EOS 850D, Japan) were obtained under identical lighting conditions. The images were blindly evaluated by three dermatologists using a 5-point hair luster grading scale (Nagase 2019). Subjective Assessment Subjective satisfaction was evaluated via a self-administered questionnaire assessing perceived changes from baseline in seven parameters: hair thickness, elasticity, luster, texture, volume, growth rate, and shedding. Safety Assessment Safety was monitored throughout the 24-week intervention period by recording adverse events, conducting clinical laboratory tests, and assessing vital signs and physical examinations. Statistical analyses All statistical analyses were performed using SPSS software (version 29.0; IBM Corp., Armonk, NY, USA). Continuous variables are presented as mean ± standard deviation (SD). Normality of data distribution was assessed using the Shapiro–Wilk or Kolmogorov–Smirnov test, as appropriate. Changes in efficacy endpoints between the Placenderm® and placebo groups were compared using an independent-samples t -test or the Wilcoxon rank-sum test, depending on data normality. To evaluate between-group differences over time and group-by-time interaction effects, repeated-measures analysis of variance (RM-ANOVA) was conducted, with group, time, and group × time interaction specified as fixed effects. All statistical tests were two-sided, and a p -value < 0.05 was considered statistically significant. Efficacy analyses were conducted on the per-protocol set (PPS), which included participants who completed the study without major protocol violations. Results Study population and baseline characteristics Among the 107 individuals screened, 100 participants with mild-to-moderate hair damage were randomly assigned (1:1) to either the Placenderm® group (n = 50) or the placebo group (n = 50) (Fig. 1 b). A total of 43 participants (86%) in the Placenderm® group and 49 participants (98%) in the placebo group completed the 24-week study. All seven withdrawals in the Placenderm® group were due to personal reasons unrelated to adverse events. The per-protocol set (PPS) for efficacy analysis comprised 92 participants (Placenderm®: n = 43; placebo: n = 49), while the safety set (SS) included all 100 randomized participants who consumed the study product at least once. No statistically significant differences were observed between the two groups in demographic characteristics or baseline clinical parameters, confirming comparability between groups (Table 2 ; all P > .05). Table 2 Subject demographics and baseline characteristics Characteristic Active Group (Placenderm®, n = 43) Control Group (Placebo, n = 49) Age (years) 40.81 ± 9.78 42.12 ± 9.32 Sex (Female), n (%) 40 (93.02) 44 (89.80) Body weight (kg) 62.75 ± 11.40 62.94 ± 13.74 Total hair damage score 9.91 ± 3.18 9.39 ± 2.65 Hair luster score 2.22 ± 0.53 2.31 ± 0.44 Scalp elasticity (CoR) 0.56 ± 0.04 0.56 ± 0.05 Caloric intake (kcal/day) 1275.50 ± 313.93 1295.46 ± 313.37 Smoking status, n (%) 3 (6.98) 3 (6.12) ≤ 10 cigarettes/day 3 (6.98) 3 (6.12) Alcohol consumption, n (%) 22 (51.16) 17 (34.69) Alcohol intake (g/week) 15.85 ± 25.97 9.62 ± 16.74 Data are presented as mean ± standard deviation or as number (percentage) of subjects, unless otherwise specified. The mean compliance rate was 97.17 ± 4.40% in the Placenderm® group and 96.67 ± 5.00% in the placebo group, with no significant intergroup differences observed at any visit ( P > .05). All participants-maintained compliance rates exceeding 80% throughout the study period. Efficacy Scalp elasticity To evaluate changes in the biomechanical properties of the scalp following intake of the study product, the mean change in scalp elasticity from baseline to Week 24 was analyzed (Fig. 2 ). Scalp elasticity was assessed using the coefficient of restitution (CoR), a biomechanical parameter that quantifies the degree of energy conservation as tissue returns to its original state after external impact. An increase in CoR is indicative of enhanced elastic recoil and improved structural robustness of scalp tissue. After 24 weeks of intervention, the mean change in CoR was 0.02 ± 0.03 in the Placenderm® group and 0.00 ± 0.03 in the placebo group. Within-group analysis showed a significant increase in CoR at Week 24 compared with baseline in the Placenderm® group, whereas no significant change was observed in the placebo group. Furthermore, between-group comparison demonstrated that the improvement in scalp elasticity was significantly greater in the Placenderm® group than in the placebo group ( P < .001). Collectively, these findings indicate that Placenderm® intake enhances the biomechanical responsiveness of the scalp, potentially reflecting improved structural integrity of the dermal extracellular matrix (ECM). Hair shaft thickness and tensile strength To evaluate the effects of the study product on the structural properties of hair, the mean change in hair shaft thickness from baseline to Week 24 was analyzed (Fig. 3 a). Hair shaft thickness was measured at the upper portion of the hair using the ASW 300 system; an increase in thickness indicates qualitative improvement in hair growth and reinforcement of the hair shaft. At Week 24, the mean change in hair shaft thickness was 0.007 ± 0.009 mm in the Placenderm® group and 0.001 ± 0.012 mm in the placebo group, showing a statistically significant intergroup difference ( P = .002). Consistent with these quantitative findings, representative macroscopic and microscopic images demonstrated visible improvements in hair shaft thickness in the Placenderm® group (Fig. 3 b). Furthermore, to assess mechanical durability, hair tensile strength was measured at Weeks 8, 16, and 24 (Fig. 3 c). Tensile strength was quantified as the maximum load (gram force, gf) sustained until breakage, serving as a key indicator of the mechanical elasticity and structural resilience of hair fibers. Compared with baseline, the mean change in tensile strength at Week 8 was 6.62 ± 6.02 gf in the Placenderm® group and − 2.07 ± 4.36 gf in the placebo group. Notably, significantly greater improvements were sustained in the Placenderm® group at Week 16 (16.05 ± 8.00 gf vs. −2.64 ± 5.10 gf) and Week 24 (26.47 ± 9.64 gf vs. −2.10 ± 7.66 gf), with significant differences observed at all time points (all P < .001). Additionally, group-by-time interaction analysis revealed that the temporal pattern of tensile strength improvement differed significantly between the two groups ( P < .001). Overall, these findings indicate that Placenderm® intake enhances hair shaft thickness and tensile strength, reflecting meaningful improvement in the structural integrity and mechanical properties of hair fibers. Ultrastructural characteristics of the hair shaft surface To evaluate ultrastructural changes in the hair shaft surface following intake of the study product, changes from baseline to Week 24 were assessed using scanning electron microscopy (SEM) images (Fig. 4 a). The condition of the hair shaft surface was evaluated using a 12-point grading scale (ranging from 1 = intact hair to 12 = exposure of the cortex due to complete loss of cuticle layers), in which lower scores indicate reduced hair shaft damage (Lee et al. 2016). Based on independent assessments conducted by three board-certified dermatologists, the mean change in damage scores from baseline to Week 24 was − 2.79 ± 0.83 points in the Placenderm® group and − 0.59 ± 0.82 points in the placebo group. The difference in score changes between the two groups was statistically significant ( P < .001). Representative SEM images illustrating the reduction in hair shaft surface damage following intake of the study product are shown in Fig. 4 b. Moreover, to quantitatively assess microstructural improvements in the hair cuticle, the mean change in cuticle surface roughness (Ra) from baseline to Week 24 was analyzed (Fig. 4 c). A decrease in Ra indicates reduced cuticle lifting and a smoother, more uniformly aligned cuticle surface. The mean change in Ra was − 21.00 ± 15.63 µm in the Placenderm® group and − 14.19 ± 15.41 µm in the placebo group, with the Placenderm® group exhibiting a significantly greater reduction in surface roughness ( P = .038). These results indicate that Placenderm® intake is associated with improvements in the morphological integrity of the hair cuticle, as evidenced by reduced surface roughness and attenuation of ultrastructural damage to the hair shaft. Optical properties of the hair shaft To quantitatively evaluate changes in the optical properties of hair following intake of the study product, the mean change in hair luster was assessed at Weeks 8, 16, and 24 using the SAMBA hair system (Fig. 5 a). This system measures light reflection and scattering from the hair surface, with higher values indicating enhanced gloss associated with improved surface smoothness. At Week 8, the mean change in hair luster from baseline was 1.48 ± 2.18 L BNT in the Placenderm® group and − 0.51 ± 2.79 L BNT in the placebo group. Similarly, at Week 16, the Placenderm® group showed a greater increase in hair luster (2.20 ± 2.30 L BNT ) compared with the placebo group (− 0.89 ± 3.70 L BNT ), with statistically significant intergroup differences observed at all time points (all P < .001). At Week 24, the mean change in hair luster remained significantly higher in the Placenderm® group (2.91 ± 3.82 L BNT ) than in the placebo group (0.10 ± 4.74 L BNT ) ( P < .001). In addition, RM-ANOVA revealed a significant group-by-time interaction, indicating that the temporal pattern of hair luster improvement differed significantly between the two groups ( P < .001). Representative images illustrating improved hair luster following intake of the study product are shown in Fig. 5 b. In parallel, visual assessments of hair gloss were conducted at Week 24 by three board-certified dermatologists (Fig. 5 c). Hair luster was evaluated using a 5-point grading scale (1 = lusterless, 5 = lustrous), where higher scores indicate clinically meaningful improvement (Nagase 2019). The mean change in visual luster scores from baseline to Week 24 was 0.92 ± 0.55 points in the Placenderm® group and 0.65 ± 0.48 points in the placebo group, with the Placenderm® group demonstrating a significantly greater improvement ( P = .021). These findings indicate that Placenderm® intake is associated with significant improvements in hair luster, as demonstrated by both instrument-based quantitative measurements and expert visual assessments, reflecting enhanced optical reflectance properties of the hair surface. Subjective assessment of hair condition To evaluate perceived changes in hair condition following intake of the study product, the mean change in participant satisfaction scores regarding overall hair health from baseline to Week 24 was analyzed (Table 3 ). An increase in the questionnaire score indicates improved subjective satisfaction with hair condition. The assessment comprised seven domains—hair thickness, elasticity, luster, texture, volume, growth rate, and reduction in hair shedding—and was conducted using a 10-point Likert scale (1 = very poor, 5 = no change, 10 = very good). Analysis revealed that the mean change in participant satisfaction scores for all seven domains was significantly greater in the Placenderm® group than in the placebo group (all P < .001). These subjective outcomes demonstrated strong concordance with the objective improvements observed through instrumental measurements and dermatologist-based visual assessments. Table 3 Participant-reported satisfaction with hair parameters Questionnaire items Active Group (Placenderm®, n = 43) Control Group (Placebo, n = 49) Hair thickness 2.79 ± 1.75 *** 1.02 ± 1.85 Hair elasticity 2.86 ± 1.58 *** 1.24 ± 2.08 Hair luster 2.53 ± 1.72 *** 1.24 ± 1.82 Hair texture 2.67 ± 1.84 *** 1.29 ± 1.99 Hair volume 3.05 ± 1.76 *** 1.22 ± 1.98 Hair growth rate 2.88 ± 1.73 *** 1.43 ± 2.11 Hair shedding 2.86 ± 1.77 *** 1.47 ± 2.07 Values are presented as mean change ± standard deviation (SD) from baseline to week 24. Participant self-assessment was scored on a 10-point Likert scale (1 = very poor, 10 = very good). *** P < 0.001 for the comparison of mean changes between the Placenderm® and placebo groups. Safety During the study period, no adverse events, serious adverse events, or study discontinuations related to the intake of the study product were reported. Clinical laboratory assessments, including hematological, blood chemistry, and urinalysis parameters, showed no statistically significant between-group differences in mean changes from baseline to Week 24 (all P > .05). In addition, no clinically meaningful abnormalities associated with the intake of the study product were observed in vital signs or body weight. These findings indicate that daily intake of Placenderm® at a dose of 500 mg for 24 weeks was not associated with safety concerns during the intervention period. Discussion Genetic and physiological factors, coupled with environmental stressors, induce diverse aging-related changes in both skin and hair, such as structural damage, reduced density, and scalp environment alterations. Hair loss, a hallmark of aging, is driven by an imbalance in the hair growth cycle—specifically, a shortened anagen phase and a prolonged telogen phase (Geyfman and Andersen 2010). This dysregulation results in diminished hair thickness, density, and cosmetic quality. As the regulatory center of the hair follicle, dermal papilla cells (DPCs) orchestrate growth cycle transitions by integrating signals from growth factors and cytokines (Sari et al. 2016) Previous nonclinical studies demonstrated that Placenderm® promotes human DPC (hDPC) proliferation and upregulates hair growth-related genes. Additionally, Placenderm® suppresses inflammatory mediators associated with catagen progression, thereby preserving follicular structure and maintaining the anagen phase. These mechanisms were further validated in in vivo models, where Placenderm® administration increased hair density and luster (Lee et al. 2025). Based on this evidence, the present study clinically evaluated the effects of oral low-molecular-weight porcine placental peptides (Placenderm®) on human scalp and hair properties. Our findings showed that Placenderm® intake for 24 weeks significantly improved scalp elasticity, suggesting enhanced structural support of the scalp tissue. Furthermore, significant time-dependent increases in hair shaft diameter and tensile strength indicate reinforced structural and mechanical durability. These clinical outcomes are consistent with nonclinical observations regarding hair cycle modulation and follicular microenvironment improvement. Additionally, SEM analysis revealed significant reductions in cuticle roughness, while optical and expert assessments confirmed improved hair luster. These results suggest that Placenderm® benefits both the internal structural integrity and the external surface characteristics of hair. Porcine placental extracts (PPE) have been reported to regulate cellular proliferation and matrix synthesis via growth factor signaling (Jash et al. 2011; Tiwary et al. 2006). The improvements observed here align with these findings, suggesting that the bioactive peptides in Placenderm® contribute to the physical maintenance of scalp and hair tissues. However, directly linking these clinical effects to specific molecular mechanisms remains limited. Future research focusing on clinically diagnosed alopecia populations would further clarify the adjunctive therapeutic potential of Placenderm®. Moreover, incorporating biomarker analyses reflecting follicular microenvironment changes will deepen the understanding of the biological mechanisms underlying Placenderm®’s efficacy. Conclusion This study demonstrated that daily intake of low-molecular-weight porcine placental peptide (Placenderm®) at a dose of 500 mg for 24 weeks significantly improved scalp elasticity and enhanced the structural and physical properties of hair. Placenderm® intake was associated with increases in hair shaft diameter and tensile strength, indicating improved mechanical durability, as well as significant improvements in hair luster through attenuation of cuticle damage and reduction in surface roughness. These objective improvements were accompanied by high levels of participant-reported satisfaction, and no treatment-related safety concerns were observed during the study period. Taken together, these findings support the potential of Placenderm® as a safe and effective functional ingredient for supporting scalp condition and improving overall hair quality. Declarations Author Contributions Substantial contributions to conception or design of the work, or the acquisition, analysis, or interpretation of data for the work: YG, AK, JL, JS, MP; Investigation and data curation: SC, JH; Supervision and project administration: HL, BK, JK, MP; Writing: YG, JK, MP. All authors have read and agreed to the published version of the manuscript. Funding This study was not supported by any external funding. Acknowledgments The authors sincerely thank all participants for their valuable contributions to this study and acknowledge the researchers at the P&K Skin Research Center for their dedicated efforts and support in conducting this research. Data availability All data supporting the findings of this study are available from the corresponding author upon reasonable request and subject to review and approval. Competing interests None. Ethical Approval This study was conducted in accordance with the principles of the Declaration of Helsinki (2013), the International Council for Harmonization Good Clinical Practice (ICH E6(R2)), and relevant institutional regulations. The protocol was approved by the Institutional Review Board of P&K Skin Research Center (IRB No. P2411-7249). Patient Consent Written informed consent was obtained from all participants prior to enrollment. Declaration of Generative AI Use During the preparation of this manuscript, the authors used ChatGPT (OpenAI, version GPT-5) solely to correct grammatical errors and improve language clarity during the manuscript writing process. The authors thoroughly reviewed and edited all generated content and take full responsibility for the final version. References Abreu CM, Marques AP (2021) Recreation of a hair follicle regenerative microenvironment: Successes and pitfalls. Bioeng Transl Med 7(1):1–18. https://doi.org/10.1002/btm2.10235 Geyfman M, Andersen B (2010) Clock genes, hair growth and aging. Aging 2:122–128. https://doi.org/10.18632/aging.100130 Hardy MH (1992) The secret life of the hair follicle. Trends Genet 8(2):55–61. https://doi.org/10.1016/0168-9525(92)90350-D Hsu YC, Li L, Fuchs E (2014) Emerging interactions between skin stem cells and their niches. 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Exp Dermatol 29(7):588–597. https://doi.org/10.1111/exd.14109 Williams R, Westgate GE, Pawlus AD et al (2021) Age-related changes in female scalp dermal sheath and dermal fibroblasts: How the hair follicle environment impacts hair aging. J Invest Dermatol 141(4S):1041–1051. https://doi.org/10.1016/j.jid.2020.11.009 Additional Declarations No competing interests reported. Cite Share Download PDF Status: Published Journal Publication published 21 Apr, 2026 Read the published version in International Journal of Peptide Research and Therapeutics → Version 1 posted Editorial decision: Revision requested 06 Mar, 2026 Reviews received at journal 04 Mar, 2026 Reviews received at journal 28 Feb, 2026 Reviewers agreed at journal 26 Feb, 2026 Reviewers agreed at journal 26 Feb, 2026 Reviewers invited by journal 24 Feb, 2026 Editor assigned by journal 21 Feb, 2026 Submission checks completed at journal 21 Feb, 2026 First submitted to journal 20 Feb, 2026 You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. 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Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-8923782","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":596958993,"identity":"d2df54ce-39fb-4db4-b262-c727d1ee1ab1","order_by":0,"name":"Yu-ri Gwon","email":"","orcid":"","institution":"Daehan Chemtech Co., Ltd.","correspondingAuthor":false,"prefix":"","firstName":"Yu-ri","middleName":"","lastName":"Gwon","suffix":""},{"id":596958994,"identity":"3f639de5-46db-48de-8d72-ce0ae4c2bf87","order_by":1,"name":"A Reum Kim","email":"","orcid":"","institution":"P\u0026K Skin Research Center Co., Ltd.","correspondingAuthor":false,"prefix":"","firstName":"A","middleName":"Reum","lastName":"Kim","suffix":""},{"id":596958995,"identity":"2a406ade-2247-4cbf-9bdf-72f7cb4af9c8","order_by":2,"name":"Ji-Hae Lee","email":"","orcid":"","institution":"UKON Solutions Co., Ltd.","correspondingAuthor":false,"prefix":"","firstName":"Ji-Hae","middleName":"","lastName":"Lee","suffix":""},{"id":596958996,"identity":"110c9c84-ff8e-4f88-99fa-87ca64268283","order_by":3,"name":"Jin Hee Shin","email":"","orcid":"","institution":"P\u0026K Skin Research Center Co., Ltd.","correspondingAuthor":false,"prefix":"","firstName":"Jin","middleName":"Hee","lastName":"Shin","suffix":""},{"id":596958997,"identity":"7a4dff9a-e822-418f-9309-6892f49b183a","order_by":4,"name":"Hae Kwang Lee","email":"","orcid":"","institution":"P\u0026K Skin Research Center Co., Ltd.","correspondingAuthor":false,"prefix":"","firstName":"Hae","middleName":"Kwang","lastName":"Lee","suffix":""},{"id":596958998,"identity":"09578e3e-1cc6-402d-89a1-3094ff00271e","order_by":5,"name":"Sun Young Choi","email":"","orcid":"","institution":"Chung-Ang University Gwangmyeong Hospital","correspondingAuthor":false,"prefix":"","firstName":"Sun","middleName":"Young","lastName":"Choi","suffix":""},{"id":596958999,"identity":"a7c33b7e-baaa-448e-be99-bd3f7a569fe3","order_by":6,"name":"Ji Yeon Hong","email":"","orcid":"","institution":"Chung-Ang University Hospital","correspondingAuthor":false,"prefix":"","firstName":"Ji","middleName":"Yeon","lastName":"Hong","suffix":""},{"id":596959000,"identity":"8b346e35-20c5-4e34-ace7-ec20f5227d0d","order_by":7,"name":"Beom Joon Kim","email":"","orcid":"","institution":"Chung-Ang University Hospital","correspondingAuthor":false,"prefix":"","firstName":"Beom","middleName":"Joon","lastName":"Kim","suffix":""},{"id":596959001,"identity":"b40ea66c-5cf3-4ace-a57d-986210c393fc","order_by":8,"name":"Jinhak Kim","email":"","orcid":"","institution":"Daehan Chemtech Co., Ltd.","correspondingAuthor":false,"prefix":"","firstName":"Jinhak","middleName":"","lastName":"Kim","suffix":""},{"id":596959002,"identity":"afc1363b-bcde-4cbc-b053-8bb8f02a04d0","order_by":9,"name":"Miyoung Park","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAA2klEQVRIiWNgGAWjYNCCAzYMEmBGAYhgI0pLGlSLAfFaDpOgRXdG7sHPFWfOJ85s7z384YMBgzw/A1vaB3xazG7kJUueuXE7cTbPuTTJGQYMhjMb2A7PwK8lx0Cy4cPtxHkSOWbMPAYMCQYH2JvxOgyoxfhnw4dzIC3Gn4nVYibZcONA4myJHANpiBa2w/i1nHmXZtlwJtl4Zs8ZM6BfJAxnNrMl49dyPPfwzYZjdrIzjvcYf/hQYSPPz95mjFcLg0AOChcYPcz4NTAw8J8hpGIUjIJRMApGPAAA90hI9/t7U/4AAAAASUVORK5CYII=","orcid":"","institution":"UKON Solutions Co., Ltd.","correspondingAuthor":true,"prefix":"","firstName":"Miyoung","middleName":"","lastName":"Park","suffix":""}],"badges":[],"createdAt":"2026-02-20 08:24:10","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-8923782/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-8923782/v1","draftVersion":[],"editorialEvents":[{"content":"https://doi.org/10.1007/s10989-026-10823-5","type":"published","date":"2026-04-21T15:57:33+00:00"}],"editorialNote":"","failedWorkflow":false,"files":[{"id":103514444,"identity":"8f6fc9d2-f096-4b74-a919-323b6d9a52c7","added_by":"auto","created_at":"2026-02-26 14:21:06","extension":"png","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":344301,"visible":true,"origin":"","legend":"\u003cp\u003e(a) Study design. (b) CONSORT flow diagram showing participant enrollment, randomization, allocation, follow-up, and analysis. PPS, per protocol set; SS, safety set.\u003c/p\u003e","description":"","filename":"1.png","url":"https://assets-eu.researchsquare.com/files/rs-8923782/v1/f60c74ee079159b94b7d888d.png"},{"id":103514610,"identity":"1266f301-cbae-4ed3-bb28-3e54b920d8e3","added_by":"auto","created_at":"2026-02-26 14:21:49","extension":"png","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":64853,"visible":true,"origin":"","legend":"\u003cp\u003eScalp elasticity, expressed as the coefficient of restitution (CoR), measured at baseline and Week 24 in the Placenderm\u003csup\u003e®\u003c/sup\u003e and placebo groups. Data are presented as mean ± standard deviation (SD). ***\u003cem\u003eP\u003c/em\u003e \u0026lt; 0.001 vs. placebo.\u003c/p\u003e","description":"","filename":"2.png","url":"https://assets-eu.researchsquare.com/files/rs-8923782/v1/4c157f3219e6597521db4659.png"},{"id":103514548,"identity":"ba15e7ec-7c56-49b0-9cc2-696b43de6c89","added_by":"auto","created_at":"2026-02-26 14:21:18","extension":"png","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":681705,"visible":true,"origin":"","legend":"\u003cp\u003eHair physical properties in the Placenderm\u003csup\u003e®\u003c/sup\u003e and placebo groups. (a) Hair shaft diameter measured at baseline and Week 24. (b) Representative images of hair density. (c) Hair tensile strength assessed at Weeks 8, 16, and 24 relative to baseline. Data are presented as mean ± SD. **\u003cem\u003eP\u003c/em\u003e \u0026lt; 0.01, ***\u003cem\u003eP\u003c/em\u003e \u0026lt; 0.001 vs. placebo.\u003c/p\u003e","description":"","filename":"3.png","url":"https://assets-eu.researchsquare.com/files/rs-8923782/v1/4d01d77240427c0f4a78b512.png"},{"id":103514549,"identity":"d6c609e7-d86e-4bdc-85e1-39cb57e96aa9","added_by":"auto","created_at":"2026-02-26 14:21:18","extension":"png","order_by":4,"title":"Figure 4","display":"","copyAsset":false,"role":"figure","size":594793,"visible":true,"origin":"","legend":"\u003cp\u003eHair shaft surface characteristics in the Placenderm\u003csup\u003e®\u003c/sup\u003e and placebo groups. (a) Hair shaft surface damage scores evaluated by scanning electron microscopy (SEM) at baseline and Week 24. (b) Representative SEM images showing hair shaft surface microstructure. (c) Hair surface roughness (Ra) assessed at Week 24 relative to baseline. Data are presented as mean ± SD. *\u003cem\u003eP\u003c/em\u003e \u0026lt; 0.05, ***\u003cem\u003eP\u003c/em\u003e \u0026lt; 0.001 vs. placebo.\u003c/p\u003e","description":"","filename":"4.png","url":"https://assets-eu.researchsquare.com/files/rs-8923782/v1/1be8a8b237ba5ff62bc81d15.png"},{"id":103515766,"identity":"a820c2c4-5876-49c9-8728-f32847650389","added_by":"auto","created_at":"2026-02-26 14:24:53","extension":"png","order_by":5,"title":"Figure 5","display":"","copyAsset":false,"role":"figure","size":696035,"visible":true,"origin":"","legend":"\u003cp\u003eHair luster in the Placenderm\u003csup\u003e®\u003c/sup\u003e and placebo groups. (a) Hair luster (L\u003csub\u003eBNT\u003c/sub\u003e) measured using the SAMBA Hair System at Weeks 8, 16, and 24 relative to baseline. (b) Representative hair luster images obtained from the SAMBA Hair System. (c) Hair luster scores assessed by expert visual evaluation at baseline and Week 24. Data are presented as mean ± SD. *\u003cem\u003eP\u003c/em\u003e \u0026lt; 0.05, ***\u003cem\u003eP\u003c/em\u003e \u0026lt; 0.001 vs. placebo.\u003c/p\u003e","description":"","filename":"5.png","url":"https://assets-eu.researchsquare.com/files/rs-8923782/v1/2e73576875af752c90e7b422.png"},{"id":107927760,"identity":"4c955f8c-8a2f-4fda-9058-ae332f0eda3c","added_by":"auto","created_at":"2026-04-27 16:03:54","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":3449822,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-8923782/v1/66ea0499-0bdd-46b5-ade0-a510ed2ed704.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"\u003cp\u003eImprovements in scalp elasticity and hair properties following supplementation with low-molecular-weight porcine placental peptides (Placenderm®): A randomized, double-blind, placebo-controlled clinical trial\u003c/p\u003e","fulltext":[{"header":"Introduction","content":"\u003cp\u003eThe human scalp is a specialized integumentary structure characterized by a high density of terminal hair follicles embedded within a dense collagenous dermal extracellular matrix (ECM). Increasing evidence indicates that follicular integrity is not solely governed by epithelial stem cell activity but is critically dependent on the structural and biochemical properties of the surrounding dermal niche (Hardy 1992; Abreu and Marques 2021; Hsu et al. 2014). The perifollicular ECM provides mechanical support and regulatory cues necessary for homeostatic hair cycling; its remodeling or degradation has been implicated in follicular miniaturization and progressive hair thinning (Piccini et al. 2022; Pappelbaum et al. 2024).\u003c/p\u003e \u003cp\u003eUnder normal conditions, the scalp is partially protected from UV exposure by hair coverage and exhibits a thicker dermis compared to other anatomical sites. Each follicular unit typically produces two to three terminal hairs, contributing to the mechanical stability of the hair shaft and overall hair quality (Tosti and Schwartz 2021). The biological mechanisms underlying scalp aging largely parallel those of general skin aging and are characterized by reduced tissue flexibility and diminished elastic recoil. These degenerative transitions involve the flattening of the dermo-epidermal junction and the loss of rete ridges. Furthermore, aging accentuates the structural distinction between the papillary and reticular dermis, a phenomenon closely associated with collagen denaturation within the papillary dermal layer (Williams et al. 2021; Ralph 2021). In addition to providing structural support, the dermal collagen network contributes to biomechanical tension that is essential for optimal dermal papilla function and coordinated hair cycle regulation.\u003c/p\u003e \u003cp\u003eThese age-related changes, particularly the compositional remodeling of the ECM, not only weaken the structural support of hair follicles but also impair nutrient delivery via the perifollicular microvasculature. Specifically, senescence of the ECM surrounding the dermal papilla (DP)\u0026mdash;the central regulator of hair growth\u0026mdash;disrupts the follicular nutritional niche, adversely affecting hair cycle regulation and follicle size maintenance (Williams et al. 2020; Jang et al. 2023; Kligman 1988). Such molecular shifts are linked to follicular miniaturization, functional regression, and hair shaft thinning. Collectively, these changes compromise the integrity of the perifollicular dermal niche, which is critical for maintaining follicular competence and structural stability. When combined with androgenetic factors, these changes manifest as perifollicular fibrosis and inflammatory responses. Ultimately, these alterations affect hair density, diameter, and luster, thereby impacting manageability and appearance. This highlights the clinical necessity for interventions that address both the physiological and psychosocial aspects of hair health, as visible hair thinning often diminishes self-esteem and psychological well-being (Jeong et al. 2011; Tr\u0026uuml;eb et al. 2018).\u003c/p\u003e \u003cp\u003ePorcine placenta extracts, obtained through enzymatic digestion or acid hydrolysis, contain a diverse array of bioactive constituents, including amino acids, peptides, and growth factors (Pogozhykh et al. 2018). Among these, low-molecular-weight porcine placenta peptides (Placenderm\u0026reg;) have been shown to exert antioxidant and anti-inflammatory effects, suppress matrix metalloproteinases (MMPs), and stimulate fibroblast activity to induce procollagen type I synthesis (Sim et al. 2024). Clinical evidence suggests that Placenderm\u0026reg; supplementation significantly improves skin hydration and elasticity in middle-aged and older adults (Nguyen et al. 2025). Furthermore, Placenderm\u0026reg; is reported to upregulate insulin-like growth factor-1 (IGF-1) and vascular endothelial growth factor (VEGF), potentially enhancing perifollicular angiogenesis. Through modulation of the Wnt/β-catenin signaling pathway, Placenderm\u0026reg; may contribute to the remodeling of the dermal microenvironment and the restoration of physiological function in miniaturized follicles (Lee et al. 2025).\u003c/p\u003e \u003cp\u003eBased on this evidence, the present study aimed to evaluate whether oral supplementation with Placenderm\u0026reg; improves scalp elasticity and hair physical properties, potentially through modulation of the dermal ECM and follicular niche. To this end, a randomized clinical trial was conducted in adults with mild-to-moderate hair damage to quantitatively assess changes in scalp elasticity, hair thickness, and luster, while confirming the efficacy and safety of the intervention.\u003c/p\u003e"},{"header":"Methods","content":"\u003cdiv id=\"Sec3\" class=\"Section2\"\u003e \u003ch2\u003eStudy design\u003c/h2\u003e \u003cp\u003eThis randomized, double-blind, placebo-controlled, parallel-group clinical trial was designed to evaluate the efficacy and safety of oral low-molecular-weight porcine placental peptides (Placenderm\u0026reg;) in adults (aged 19\u0026ndash;60 years) with mild to moderate hair damage. The trial was conducted at a single clinical research center in the Republic of Korea. Following the screening of 107 candidates, 100 eligible participants meeting the predefined inclusion and exclusion criteria were enrolled. Participants were randomly assigned in a 1:1 ratio to receive either Placenderm\u0026reg; (500 mg/day) or a matching placebo for 24 weeks. Efficacy and safety assessments were performed at baseline and at Weeks 8, 16, and 24 (Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003ea).\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003e The study was conducted in accordance with the ethical principles of the Declaration of Helsinki and the International Council for Harmonisation (ICH) Guidelines for Good Clinical Practice (GCP). The study protocol, informed consent forms, and all relevant documents were approved by the Institutional Review Board (IRB) of the study site. Written informed consent was obtained from all participants prior to enrollment.\u003c/p\u003e \u003c/div\u003e\n\u003ch3\u003eParticipants\u003c/h3\u003e\n\u003cp\u003eEligible participants were required to meet all of the following inclusion criteria: adults without diagnosed hair loss disorders who exhibited mild to moderate hair damage, defined by a hair luster score of \u0026le;\u0026thinsp;3 on a standardized visual assessment scale and a total hair damage score of \u0026lt;\u0026thinsp;18 (Marsh et al. 2015; Nagase 2019). During the study period, all physical and chemical hair treatments, including perming and dyeing, were prohibited, and participants were restricted to using only the provided standardized hair care products to minimize external confounding factors. Exclusion criteria included diagnosed hair loss disorders (e.g., androgenetic alopecia); chronic or infectious scalp diseases or generalized pruritus of psychiatric or neurological origin; nutritional deficiencies due to extreme dieting or gastrectomy; prior surgical hair restoration; and recent use of systemic corticosteroids, vasodilators, or diuretics within 1 month, or 5-α reductase inhibitors (dutasteride or finasteride) within 6 months prior to screening.\u003c/p\u003e\n\u003ch3\u003eRandomization, Blinding, and Intervention\u003c/h3\u003e\n\u003cp\u003e Participants were randomly assigned in a 1:1 ratio to either the Placenderm\u0026reg; or placebo group using a computer-generated block randomization scheme implemented with IBM SPSS Statistics (version 29.0). To ensure a robust double-blind design, the investigational product and placebo were manufactured to be identical in appearance, color, odor, and taste, rendering them indistinguishable (Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e). The investigational product and placebo were supplied by Daehan Chemtech Co., Ltd. (Korea) and provided in blinded, coded kits to maintain strict allocation concealment. Neither the participants nor the investigators involved in outcome assessment were aware of group assignments until study completion and database lock. Throughout the 24-week intervention period, participants were instructed to consume the assigned product once daily at bedtime, in accordance with the predefined dosing regimen.\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab1\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 1\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eComposition of the Investigational and Placebo Products (%)\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"3\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eIngredient\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eActive Group\u003c/p\u003e \u003cp\u003e(Placenderm\u0026reg;)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eControl Group\u003c/p\u003e \u003cp\u003e(Placebo)\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003ePlacenderm\u0026reg;\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e50.00\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eMaltodextrin\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e50.00\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCorn starch\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e3.00\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e3.00\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eMicrocrystalline cellulose\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e26.26\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e26.26\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCarboxymethylcellulose calcium\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e5.00\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e5.00\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eIsomalt\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e9.00\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e9.00\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eMagnesium stearate\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e1.00\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e1.00\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eSilicon dioxide\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e1.50\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e1.50\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eHydroxypropyl methylcellulose\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e2.40\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e2.40\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eProprietary blend\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e1.00\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e1.00\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eTitanium dioxide\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0.60\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0.60\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eGlycerin\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0.24\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0.24\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eTotal\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e100.00\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e100.00\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003ctfoot\u003e \u003ctr\u003e\u003ctd colspan=\"3\"\u003ePlacenderm\u0026reg; and placebo tablets were indistinguishable in appearance, composition (excipients), and administration protocol.\u003c/td\u003e\u003c/tr\u003e \u003c/tfoot\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e\n\u003ch3\u003eEfficacy and Safety Evaluations\u003c/h3\u003e\n\u003cp\u003eAll efficacy assessments were conducted after approximately 2 hours of acclimatization in a climate-controlled environment (temperature 22\u0026thinsp;\u0026plusmn;\u0026thinsp;2\u0026deg;C, relative humidity 50\u0026thinsp;\u0026plusmn;\u0026thinsp;5%).\u003c/p\u003e\n\u003ch3\u003eScalp Elasticity\u003c/h3\u003e\n\u003cp\u003eScalp elasticity was evaluated at the vertex using a Ballistometer (BLS780; Dia-Stron Ltd., UK). The vertex was anatomically defined as the intersection of a vertical line drawn from the midpoint between both ears and the central parting line of the forehead. The mean value of three consecutive measurements at the same site was used for analysis.\u003c/p\u003e \u003cdiv id=\"Sec8\" class=\"Section2\"\u003e \u003ch2\u003eHair Physical Properties\u003c/h2\u003e \u003cp\u003eHair shaft diameter was measured using the ASW 300 system (AramHuvis, Korea). Hair samples were collected from three scalp regions (left temporal, right temporal, and occipital), and the diameter of the proximal portion of the hair shaft was determined. Hair tensile strength was assessed using a universal testing machine (UNITEST M1; TESTONE Co., Ltd., Korea). Hair samples collected from the same regions were subjected to longitudinal tension until fracture, and the maximum load was recorded.\u003c/p\u003e \u003c/div\u003e\n\u003ch3\u003eHair Surface Morphology and Roughness\u003c/h3\u003e\n\u003cp\u003eHair shaft surface morphology was examined using scanning electron microscopy (SEM; EM-30, Coxem, Korea). SEM images were independently evaluated by three dermatologists using a validated 12-point hair damage grading scale (Lee et al. 2016). In addition, the mean arithmetic surface roughness (Rₐ) was quantitatively calculated from SEM images using ImageJ software (National Institutes of Health, USA).\u003c/p\u003e\n\u003ch3\u003eHair Luster\u003c/h3\u003e\n\u003cp\u003eHair luster was quantitatively evaluated using the SAMBA hair system (Bossa Nova Technologies, USA) by measuring reflected light intensity from randomly selected hair bundles. Additionally, standardized digital photographs (Canon EOS 850D, Japan) were obtained under identical lighting conditions. The images were blindly evaluated by three dermatologists using a 5-point hair luster grading scale (Nagase 2019).\u003c/p\u003e \u003cdiv id=\"Sec11\" class=\"Section2\"\u003e \u003ch2\u003eSubjective Assessment\u003c/h2\u003e \u003cp\u003eSubjective satisfaction was evaluated via a self-administered questionnaire assessing perceived changes from baseline in seven parameters: hair thickness, elasticity, luster, texture, volume, growth rate, and shedding.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec12\" class=\"Section2\"\u003e \u003ch2\u003eSafety Assessment\u003c/h2\u003e \u003cp\u003eSafety was monitored throughout the 24-week intervention period by recording adverse events, conducting clinical laboratory tests, and assessing vital signs and physical examinations.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec13\" class=\"Section2\"\u003e \u003ch2\u003eStatistical analyses\u003c/h2\u003e \u003cp\u003eAll statistical analyses were performed using SPSS software (version 29.0; IBM Corp., Armonk, NY, USA). Continuous variables are presented as mean\u0026thinsp;\u0026plusmn;\u0026thinsp;standard deviation (SD). Normality of data distribution was assessed using the Shapiro\u0026ndash;Wilk or Kolmogorov\u0026ndash;Smirnov test, as appropriate. Changes in efficacy endpoints between the Placenderm\u0026reg; and placebo groups were compared using an independent-samples \u003cem\u003et\u003c/em\u003e-test or the Wilcoxon rank-sum test, depending on data normality. To evaluate between-group differences over time and group-by-time interaction effects, repeated-measures analysis of variance (RM-ANOVA) was conducted, with group, time, and group \u0026times; time interaction specified as fixed effects. All statistical tests were two-sided, and a \u003cem\u003ep\u003c/em\u003e-value\u0026thinsp;\u0026lt;\u0026thinsp;0.05 was considered statistically significant. Efficacy analyses were conducted on the per-protocol set (PPS), which included participants who completed the study without major protocol violations.\u003c/p\u003e \u003c/div\u003e"},{"header":"Results","content":"\u003cdiv id=\"Sec15\" class=\"Section2\"\u003e \u003ch2\u003eStudy population and baseline characteristics\u003c/h2\u003e \u003cp\u003eAmong the 107 individuals screened, 100 participants with mild-to-moderate hair damage were randomly assigned (1:1) to either the Placenderm\u0026reg; group (n\u0026thinsp;=\u0026thinsp;50) or the placebo group (n\u0026thinsp;=\u0026thinsp;50) (Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003eb). A total of 43 participants (86%) in the Placenderm\u0026reg; group and 49 participants (98%) in the placebo group completed the 24-week study. All seven withdrawals in the Placenderm\u0026reg; group were due to personal reasons unrelated to adverse events.\u003c/p\u003e \u003cp\u003eThe per-protocol set (PPS) for efficacy analysis comprised 92 participants (Placenderm\u0026reg;: n\u0026thinsp;=\u0026thinsp;43; placebo: n\u0026thinsp;=\u0026thinsp;49), while the safety set (SS) included all 100 randomized participants who consumed the study product at least once. No statistically significant differences were observed between the two groups in demographic characteristics or baseline clinical parameters, confirming comparability between groups (Table\u0026nbsp;\u003cspan refid=\"Tab2\" class=\"InternalRef\"\u003e2\u003c/span\u003e; all \u003cem\u003eP\u003c/em\u003e \u0026gt; .05).\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab2\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 2\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eSubject demographics and baseline characteristics\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"3\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCharacteristic\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eActive Group\u003c/p\u003e \u003cp\u003e(Placenderm\u0026reg;, n\u0026thinsp;=\u0026thinsp;43)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eControl Group\u003c/p\u003e \u003cp\u003e(Placebo, n\u0026thinsp;=\u0026thinsp;49)\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eAge (years)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e40.81\u0026thinsp;\u0026plusmn;\u0026thinsp;9.78\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e42.12\u0026thinsp;\u0026plusmn;\u0026thinsp;9.32\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eSex (Female), n (%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e40 (93.02)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e44 (89.80)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eBody weight (kg)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e62.75\u0026thinsp;\u0026plusmn;\u0026thinsp;11.40\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e62.94\u0026thinsp;\u0026plusmn;\u0026thinsp;13.74\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eTotal hair damage score\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e9.91\u0026thinsp;\u0026plusmn;\u0026thinsp;3.18\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e9.39\u0026thinsp;\u0026plusmn;\u0026thinsp;2.65\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eHair luster score\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e2.22\u0026thinsp;\u0026plusmn;\u0026thinsp;0.53\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e2.31\u0026thinsp;\u0026plusmn;\u0026thinsp;0.44\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eScalp elasticity (CoR)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0.56\u0026thinsp;\u0026plusmn;\u0026thinsp;0.04\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0.56\u0026thinsp;\u0026plusmn;\u0026thinsp;0.05\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCaloric intake (kcal/day)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e1275.50\u0026thinsp;\u0026plusmn;\u0026thinsp;313.93\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e1295.46\u0026thinsp;\u0026plusmn;\u0026thinsp;313.37\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eSmoking status, n (%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e3 (6.98)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e3 (6.12)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u0026le;\u0026thinsp;10 cigarettes/day\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e3 (6.98)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e3 (6.12)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eAlcohol consumption, n (%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e22 (51.16)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e17 (34.69)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eAlcohol intake (g/week)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e15.85\u0026thinsp;\u0026plusmn;\u0026thinsp;25.97\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e9.62\u0026thinsp;\u0026plusmn;\u0026thinsp;16.74\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003ctfoot\u003e \u003ctr\u003e\u003ctd colspan=\"3\"\u003eData are presented as mean\u0026thinsp;\u0026plusmn;\u0026thinsp;standard deviation or as number (percentage) of subjects, unless otherwise specified.\u003c/td\u003e\u003c/tr\u003e \u003c/tfoot\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cp\u003eThe mean compliance rate was 97.17\u0026thinsp;\u0026plusmn;\u0026thinsp;4.40% in the Placenderm\u0026reg; group and 96.67\u0026thinsp;\u0026plusmn;\u0026thinsp;5.00% in the placebo group, with no significant intergroup differences observed at any visit (\u003cem\u003eP\u003c/em\u003e \u0026gt; .05). All participants-maintained compliance rates exceeding 80% throughout the study period.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec16\" class=\"Section2\"\u003e \u003ch2\u003eEfficacy\u003c/h2\u003e \u003cdiv id=\"Sec17\" class=\"Section3\"\u003e \u003ch2\u003eScalp elasticity\u003c/h2\u003e \u003cp\u003eTo evaluate changes in the biomechanical properties of the scalp following intake of the study product, the mean change in scalp elasticity from baseline to Week 24 was analyzed (Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003e). Scalp elasticity was assessed using the coefficient of restitution (CoR), a biomechanical parameter that quantifies the degree of energy conservation as tissue returns to its original state after external impact. An increase in CoR is indicative of enhanced elastic recoil and improved structural robustness of scalp tissue. After 24 weeks of intervention, the mean change in CoR was 0.02\u0026thinsp;\u0026plusmn;\u0026thinsp;0.03 in the Placenderm\u0026reg; group and 0.00\u0026thinsp;\u0026plusmn;\u0026thinsp;0.03 in the placebo group. Within-group analysis showed a significant increase in CoR at Week 24 compared with baseline in the Placenderm\u0026reg; group, whereas no significant change was observed in the placebo group. Furthermore, between-group comparison demonstrated that the improvement in scalp elasticity was significantly greater in the Placenderm\u0026reg; group than in the placebo group (\u003cem\u003eP\u003c/em\u003e \u0026lt; .001). Collectively, these findings indicate that Placenderm\u0026reg; intake enhances the biomechanical responsiveness of the scalp, potentially reflecting improved structural integrity of the dermal extracellular matrix (ECM).\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv id=\"Sec18\" class=\"Section2\"\u003e \u003ch2\u003eHair shaft thickness and tensile strength\u003c/h2\u003e \u003cp\u003eTo evaluate the effects of the study product on the structural properties of hair, the mean change in hair shaft thickness from baseline to Week 24 was analyzed (Fig.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003ea). Hair shaft thickness was measured at the upper portion of the hair using the ASW 300 system; an increase in thickness indicates qualitative improvement in hair growth and reinforcement of the hair shaft. At Week 24, the mean change in hair shaft thickness was 0.007\u0026thinsp;\u0026plusmn;\u0026thinsp;0.009 mm in the Placenderm\u0026reg; group and 0.001\u0026thinsp;\u0026plusmn;\u0026thinsp;0.012 mm in the placebo group, showing a statistically significant intergroup difference (\u003cem\u003eP\u003c/em\u003e = .002). Consistent with these quantitative findings, representative macroscopic and microscopic images demonstrated visible improvements in hair shaft thickness in the Placenderm\u0026reg; group (Fig.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003eb).\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003eFurthermore, to assess mechanical durability, hair tensile strength was measured at Weeks 8, 16, and 24 (Fig.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003ec). Tensile strength was quantified as the maximum load (gram force, gf) sustained until breakage, serving as a key indicator of the mechanical elasticity and structural resilience of hair fibers. Compared with baseline, the mean change in tensile strength at Week 8 was 6.62\u0026thinsp;\u0026plusmn;\u0026thinsp;6.02 gf in the Placenderm\u0026reg; group and \u0026minus;\u0026thinsp;2.07\u0026thinsp;\u0026plusmn;\u0026thinsp;4.36 gf in the placebo group. Notably, significantly greater improvements were sustained in the Placenderm\u0026reg; group at Week 16 (16.05\u0026thinsp;\u0026plusmn;\u0026thinsp;8.00 gf vs. \u0026minus;2.64\u0026thinsp;\u0026plusmn;\u0026thinsp;5.10 gf) and Week 24 (26.47\u0026thinsp;\u0026plusmn;\u0026thinsp;9.64 gf vs. \u0026minus;2.10\u0026thinsp;\u0026plusmn;\u0026thinsp;7.66 gf), with significant differences observed at all time points (all \u003cem\u003eP\u003c/em\u003e \u0026lt; .001). Additionally, group-by-time interaction analysis revealed that the temporal pattern of tensile strength improvement differed significantly between the two groups (\u003cem\u003eP\u003c/em\u003e \u0026lt; .001). Overall, these findings indicate that Placenderm\u0026reg; intake enhances hair shaft thickness and tensile strength, reflecting meaningful improvement in the structural integrity and mechanical properties of hair fibers.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec19\" class=\"Section2\"\u003e \u003ch2\u003eUltrastructural characteristics of the hair shaft surface\u003c/h2\u003e \u003cp\u003eTo evaluate ultrastructural changes in the hair shaft surface following intake of the study product, changes from baseline to Week 24 were assessed using scanning electron microscopy (SEM) images (Fig.\u0026nbsp;\u003cspan refid=\"Fig4\" class=\"InternalRef\"\u003e4\u003c/span\u003ea). The condition of the hair shaft surface was evaluated using a 12-point grading scale (ranging from 1\u0026thinsp;=\u0026thinsp;intact hair to 12\u0026thinsp;=\u0026thinsp;exposure of the cortex due to complete loss of cuticle layers), in which lower scores indicate reduced hair shaft damage (Lee et al. 2016). Based on independent assessments conducted by three board-certified dermatologists, the mean change in damage scores from baseline to Week 24 was \u0026minus;\u0026thinsp;2.79\u0026thinsp;\u0026plusmn;\u0026thinsp;0.83 points in the Placenderm\u0026reg; group and \u0026minus;\u0026thinsp;0.59\u0026thinsp;\u0026plusmn;\u0026thinsp;0.82 points in the placebo group. The difference in score changes between the two groups was statistically significant (\u003cem\u003eP\u003c/em\u003e \u0026lt; .001). Representative SEM images illustrating the reduction in hair shaft surface damage following intake of the study product are shown in Fig.\u0026nbsp;\u003cspan refid=\"Fig4\" class=\"InternalRef\"\u003e4\u003c/span\u003eb.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003eMoreover, to quantitatively assess microstructural improvements in the hair cuticle, the mean change in cuticle surface roughness (Ra) from baseline to Week 24 was analyzed (Fig.\u0026nbsp;\u003cspan refid=\"Fig4\" class=\"InternalRef\"\u003e4\u003c/span\u003ec). A decrease in Ra indicates reduced cuticle lifting and a smoother, more uniformly aligned cuticle surface. The mean change in Ra was \u0026minus;\u0026thinsp;21.00\u0026thinsp;\u0026plusmn;\u0026thinsp;15.63 \u0026micro;m in the Placenderm\u0026reg; group and \u0026minus;\u0026thinsp;14.19\u0026thinsp;\u0026plusmn;\u0026thinsp;15.41 \u0026micro;m in the placebo group, with the Placenderm\u0026reg; group exhibiting a significantly greater reduction in surface roughness (\u003cem\u003eP\u003c/em\u003e = .038). These results indicate that Placenderm\u0026reg; intake is associated with improvements in the morphological integrity of the hair cuticle, as evidenced by reduced surface roughness and attenuation of ultrastructural damage to the hair shaft.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec20\" class=\"Section2\"\u003e \u003ch2\u003eOptical properties of the hair shaft\u003c/h2\u003e \u003cp\u003eTo quantitatively evaluate changes in the optical properties of hair following intake of the study product, the mean change in hair luster was assessed at Weeks 8, 16, and 24 using the SAMBA hair system (Fig.\u0026nbsp;\u003cspan refid=\"Fig5\" class=\"InternalRef\"\u003e5\u003c/span\u003ea). This system measures light reflection and scattering from the hair surface, with higher values indicating enhanced gloss associated with improved surface smoothness. At Week 8, the mean change in hair luster from baseline was 1.48\u0026thinsp;\u0026plusmn;\u0026thinsp;2.18 L\u003csub\u003eBNT\u003c/sub\u003e in the Placenderm\u0026reg; group and \u0026minus;\u0026thinsp;0.51\u0026thinsp;\u0026plusmn;\u0026thinsp;2.79 L\u003csub\u003eBNT\u003c/sub\u003e in the placebo group. Similarly, at Week 16, the Placenderm\u0026reg; group showed a greater increase in hair luster (2.20\u0026thinsp;\u0026plusmn;\u0026thinsp;2.30 L\u003csub\u003eBNT\u003c/sub\u003e) compared with the placebo group (\u0026minus;\u0026thinsp;0.89\u0026thinsp;\u0026plusmn;\u0026thinsp;3.70 L\u003csub\u003eBNT\u003c/sub\u003e), with statistically significant intergroup differences observed at all time points (all \u003cem\u003eP\u003c/em\u003e \u0026lt; .001). At Week 24, the mean change in hair luster remained significantly higher in the Placenderm\u0026reg; group (2.91\u0026thinsp;\u0026plusmn;\u0026thinsp;3.82 L\u003csub\u003eBNT\u003c/sub\u003e) than in the placebo group (0.10\u0026thinsp;\u0026plusmn;\u0026thinsp;4.74 L\u003csub\u003eBNT\u003c/sub\u003e) (\u003cem\u003eP\u003c/em\u003e \u0026lt; .001). In addition, RM-ANOVA revealed a significant group-by-time interaction, indicating that the temporal pattern of hair luster improvement differed significantly between the two groups (\u003cem\u003eP\u003c/em\u003e \u0026lt; .001). Representative images illustrating improved hair luster following intake of the study product are shown in Fig.\u0026nbsp;\u003cspan refid=\"Fig5\" class=\"InternalRef\"\u003e5\u003c/span\u003eb.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003eIn parallel, visual assessments of hair gloss were conducted at Week 24 by three board-certified dermatologists (Fig.\u0026nbsp;\u003cspan refid=\"Fig5\" class=\"InternalRef\"\u003e5\u003c/span\u003ec). Hair luster was evaluated using a 5-point grading scale (1\u0026thinsp;=\u0026thinsp;lusterless, 5\u0026thinsp;=\u0026thinsp;lustrous), where higher scores indicate clinically meaningful improvement (Nagase 2019). The mean change in visual luster scores from baseline to Week 24 was 0.92\u0026thinsp;\u0026plusmn;\u0026thinsp;0.55 points in the Placenderm\u0026reg; group and 0.65\u0026thinsp;\u0026plusmn;\u0026thinsp;0.48 points in the placebo group, with the Placenderm\u0026reg; group demonstrating a significantly greater improvement (\u003cem\u003eP\u003c/em\u003e = .021). These findings indicate that Placenderm\u0026reg; intake is associated with significant improvements in hair luster, as demonstrated by both instrument-based quantitative measurements and expert visual assessments, reflecting enhanced optical reflectance properties of the hair surface.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec21\" class=\"Section2\"\u003e \u003ch2\u003eSubjective assessment of hair condition\u003c/h2\u003e \u003cp\u003eTo evaluate perceived changes in hair condition following intake of the study product, the mean change in participant satisfaction scores regarding overall hair health from baseline to Week 24 was analyzed (Table\u0026nbsp;\u003cspan refid=\"Tab3\" class=\"InternalRef\"\u003e3\u003c/span\u003e). An increase in the questionnaire score indicates improved subjective satisfaction with hair condition. The assessment comprised seven domains\u0026mdash;hair thickness, elasticity, luster, texture, volume, growth rate, and reduction in hair shedding\u0026mdash;and was conducted using a 10-point Likert scale (1\u0026thinsp;=\u0026thinsp;very poor, 5\u0026thinsp;=\u0026thinsp;no change, 10\u0026thinsp;=\u0026thinsp;very good). Analysis revealed that the mean change in participant satisfaction scores for all seven domains was significantly greater in the Placenderm\u0026reg; group than in the placebo group (all \u003cem\u003eP\u003c/em\u003e \u0026lt; .001). These subjective outcomes demonstrated strong concordance with the objective improvements observed through instrumental measurements and dermatologist-based visual assessments.\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab3\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 3\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eParticipant-reported satisfaction with hair parameters\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"3\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\"\u0026plusmn;\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\"\u0026plusmn;\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eQuestionnaire items\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eActive Group\u003c/p\u003e \u003cp\u003e(Placenderm\u0026reg;, n\u0026thinsp;=\u0026thinsp;43)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eControl Group\u003c/p\u003e \u003cp\u003e(Placebo, n\u0026thinsp;=\u0026thinsp;49)\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eHair thickness\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c2\"\u003e \u003cp\u003e2.79\u0026thinsp;\u0026plusmn;\u0026thinsp;1.75\u003csup\u003e***\u003c/sup\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c3\"\u003e \u003cp\u003e1.02\u0026thinsp;\u0026plusmn;\u0026thinsp;1.85\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eHair elasticity\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c2\"\u003e \u003cp\u003e2.86\u0026thinsp;\u0026plusmn;\u0026thinsp;1.58\u003csup\u003e***\u003c/sup\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c3\"\u003e \u003cp\u003e1.24\u0026thinsp;\u0026plusmn;\u0026thinsp;2.08\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eHair luster\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c2\"\u003e \u003cp\u003e2.53\u0026thinsp;\u0026plusmn;\u0026thinsp;1.72\u003csup\u003e***\u003c/sup\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c3\"\u003e \u003cp\u003e1.24\u0026thinsp;\u0026plusmn;\u0026thinsp;1.82\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eHair texture\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c2\"\u003e \u003cp\u003e2.67\u0026thinsp;\u0026plusmn;\u0026thinsp;1.84\u003csup\u003e***\u003c/sup\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c3\"\u003e \u003cp\u003e1.29\u0026thinsp;\u0026plusmn;\u0026thinsp;1.99\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eHair volume\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c2\"\u003e \u003cp\u003e3.05\u0026thinsp;\u0026plusmn;\u0026thinsp;1.76\u003csup\u003e***\u003c/sup\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c3\"\u003e \u003cp\u003e1.22\u0026thinsp;\u0026plusmn;\u0026thinsp;1.98\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eHair growth rate\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c2\"\u003e \u003cp\u003e2.88\u0026thinsp;\u0026plusmn;\u0026thinsp;1.73\u003csup\u003e***\u003c/sup\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c3\"\u003e \u003cp\u003e1.43\u0026thinsp;\u0026plusmn;\u0026thinsp;2.11\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eHair shedding\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c2\"\u003e \u003cp\u003e2.86\u0026thinsp;\u0026plusmn;\u0026thinsp;1.77\u003csup\u003e***\u003c/sup\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c3\"\u003e \u003cp\u003e1.47\u0026thinsp;\u0026plusmn;\u0026thinsp;2.07\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003ctfoot\u003e \u003ctr\u003e\u003ctd colspan=\"3\"\u003eValues are presented as mean change\u0026thinsp;\u0026plusmn;\u0026thinsp;standard deviation (SD) from baseline to week 24. Participant self-assessment was scored on a 10-point Likert scale (1\u0026thinsp;=\u0026thinsp;very poor, 10\u0026thinsp;=\u0026thinsp;very good). \u003csup\u003e***\u003c/sup\u003e\u003cem\u003eP\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.001 for the comparison of mean changes between the Placenderm\u0026reg; and placebo groups.\u003c/td\u003e\u003c/tr\u003e \u003c/tfoot\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec22\" class=\"Section2\"\u003e \u003ch2\u003eSafety\u003c/h2\u003e \u003cp\u003eDuring the study period, no adverse events, serious adverse events, or study discontinuations related to the intake of the study product were reported. Clinical laboratory assessments, including hematological, blood chemistry, and urinalysis parameters, showed no statistically significant between-group differences in mean changes from baseline to Week 24 (all \u003cem\u003eP\u003c/em\u003e \u0026gt; .05). In addition, no clinically meaningful abnormalities associated with the intake of the study product were observed in vital signs or body weight. These findings indicate that daily intake of Placenderm\u0026reg; at a dose of 500 mg for 24 weeks was not associated with safety concerns during the intervention period.\u003c/p\u003e \u003c/div\u003e"},{"header":"Discussion","content":"\u003cp\u003eGenetic and physiological factors, coupled with environmental stressors, induce diverse aging-related changes in both skin and hair, such as structural damage, reduced density, and scalp environment alterations. Hair loss, a hallmark of aging, is driven by an imbalance in the hair growth cycle\u0026mdash;specifically, a shortened anagen phase and a prolonged telogen phase (Geyfman and Andersen 2010). This dysregulation results in diminished hair thickness, density, and cosmetic quality. As the regulatory center of the hair follicle, dermal papilla cells (DPCs) orchestrate growth cycle transitions by integrating signals from growth factors and cytokines (Sari et al. 2016)\u003c/p\u003e \u003cp\u003ePrevious nonclinical studies demonstrated that Placenderm\u0026reg; promotes human DPC (hDPC) proliferation and upregulates hair growth-related genes. Additionally, Placenderm\u0026reg; suppresses inflammatory mediators associated with catagen progression, thereby preserving follicular structure and maintaining the anagen phase. These mechanisms were further validated in \u003cem\u003ein vivo\u003c/em\u003e models, where Placenderm\u0026reg; administration increased hair density and luster (Lee et al. 2025). Based on this evidence, the present study clinically evaluated the effects of oral low-molecular-weight porcine placental peptides (Placenderm\u0026reg;) on human scalp and hair properties. Our findings showed that Placenderm\u0026reg; intake for 24 weeks significantly improved scalp elasticity, suggesting enhanced structural support of the scalp tissue. Furthermore, significant time-dependent increases in hair shaft diameter and tensile strength indicate reinforced structural and mechanical durability. These clinical outcomes are consistent with nonclinical observations regarding hair cycle modulation and follicular microenvironment improvement. Additionally, SEM analysis revealed significant reductions in cuticle roughness, while optical and expert assessments confirmed improved hair luster. These results suggest that Placenderm\u0026reg; benefits both the internal structural integrity and the external surface characteristics of hair. Porcine placental extracts (PPE) have been reported to regulate cellular proliferation and matrix synthesis via growth factor signaling (Jash et al. 2011; Tiwary et al. 2006). The improvements observed here align with these findings, suggesting that the bioactive peptides in Placenderm\u0026reg; contribute to the physical maintenance of scalp and hair tissues.\u003c/p\u003e \u003cp\u003eHowever, directly linking these clinical effects to specific molecular mechanisms remains limited. Future research focusing on clinically diagnosed alopecia populations would further clarify the adjunctive therapeutic potential of Placenderm\u0026reg;. Moreover, incorporating biomarker analyses reflecting follicular microenvironment changes will deepen the understanding of the biological mechanisms underlying Placenderm\u0026reg;\u0026rsquo;s efficacy.\u003c/p\u003e"},{"header":"Conclusion","content":"\u003cp\u003eThis study demonstrated that daily intake of low-molecular-weight porcine placental peptide (Placenderm\u0026reg;) at a dose of 500 mg for 24 weeks significantly improved scalp elasticity and enhanced the structural and physical properties of hair. Placenderm\u0026reg; intake was associated with increases in hair shaft diameter and tensile strength, indicating improved mechanical durability, as well as significant improvements in hair luster through attenuation of cuticle damage and reduction in surface roughness. These objective improvements were accompanied by high levels of participant-reported satisfaction, and no treatment-related safety concerns were observed during the study period. Taken together, these findings support the potential of Placenderm\u0026reg; as a safe and effective functional ingredient for supporting scalp condition and improving overall hair quality.\u003c/p\u003e"},{"header":"Declarations","content":"\u003cp\u003e\u003cstrong\u003eAuthor Contributions\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eSubstantial contributions to conception or design of the work, or the acquisition, analysis, or interpretation of data for the work: YG, AK, JL, JS, MP; Investigation and data curation: SC, JH; Supervision and project administration: HL, BK, JK, MP; Writing: YG, JK, MP. All authors have read and agreed to the published version of the manuscript.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eFunding\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThis study was not supported by any external funding.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAcknowledgments\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe authors sincerely thank all participants for their valuable contributions to this study and acknowledge the researchers at the P\u0026amp;K Skin Research Center for their dedicated efforts and support in conducting this research.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eData availability\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eAll data supporting the findings of this study are available from the corresponding author upon reasonable request and subject to review and approval.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eCompeting interests\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eNone.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eEthical Approval\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThis study was conducted in accordance with the principles of the Declaration of Helsinki (2013), the International Council for Harmonization Good Clinical Practice (ICH E6(R2)), and relevant institutional regulations. The protocol was approved by the Institutional Review Board of P\u0026amp;K Skin Research Center (IRB No. P2411-7249).\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003ePatient Consent\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eWritten informed consent was obtained from all participants prior to enrollment.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eDeclaration of Generative AI Use\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eDuring the preparation of this manuscript, the authors used ChatGPT (OpenAI, version GPT-5) solely to correct grammatical errors and improve language clarity during the manuscript writing process. The authors thoroughly reviewed and edited all generated content and take full responsibility for the final version.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\u003cli\u003e\u003cspan\u003eAbreu CM, Marques AP (2021) Recreation of a hair follicle regenerative microenvironment: Successes and pitfalls. Bioeng Transl Med 7(1):1\u0026ndash;18. https://doi.org/10.1002/btm2.10235\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eGeyfman M, Andersen B (2010) Clock genes, hair growth and aging. Aging 2:122\u0026ndash;128. https://doi.org/10.18632/aging.100130\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eHardy MH (1992) The secret life of the hair follicle. Trends Genet 8(2):55\u0026ndash;61. https://doi.org/10.1016/0168-9525(92)90350-D\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eHsu YC, Li L, Fuchs E (2014) Emerging interactions between skin stem cells and their niches. Nat Med 20(8):847\u0026ndash;856. https://doi.org/10.1038/nm.3643\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eJang H, Jo Y, Lee JH, Choi S (2023) Aging of hair follicle stem cells and their niches. BMB Rep 56(1):2\u0026ndash;9. https://doi.org/10.5483/BMBRep.2022-0183\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eJash A, Kwon HK, Sahoo A et al (2011) Topical application of porcine placenta extract inhibits the progression of experimental contact hypersensitivity. J Ethnopharmacol 133(2):654\u0026ndash;662. https://doi.org/10.1016/j.jep.2010.10.054\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eJeong KH, Kim KS, Lee GJ et al (2011) Investigation of aging effects in human hair using atomic force microscopy. Skin Res Technol 11:63\u0026ndash;68. https://doi.org/10.1111/j.1600-0846.2010.00466.x\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eKligman AM (1988) The comparative histopathology of male-pattern baldness and senescent baldness. 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Springer https://doi.org/10.1007/978-3-319-18386-2\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eNagase S (2019) Hair Structures Affecting Hair Appearance. Cosmetics 6:43. https://doi.org/10.3390/cosmetics6030043\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eNguyen NH, Lee YI, Chau NH et al (2025) Porcine placenta peptides as a complementary functional food for skin rejuvenation: A 12-week randomized, double-blind, placebo-controlled trial. Complement Ther Med 95:103271. https://doi.org/10.1016/j.ctim.2025.103271\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003ePappelbaum KI, Virgillio N, Epping L et al (2024) Revealing novel insights on how oral supplementation with bioactive collagen peptides supports hair follicle preservation. J Funct Foods 116:106124. https://doi.org/10.1016/j.jff.2024.106124\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003ePiccini I, Sousa M, Altendorf S et al (2022) Intermediate hair follicles from patients with female pattern hair loss are associated with nutrient insufficiency and a quiescent metabolic phenotype. Nutrients 14:3357. https://doi.org/10.3390/nu14163357\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003ePogozhykh O, Prokopyuk V, Figueiredo C, Pogozhykh D (2018) Placenta and placental derivatives in regenerative therapies: Experimental studies, history, and prospects. Stem Cells Int 2018;4837930. https://doi.org/10.1155/2018/4837930\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eRalph MT (2021) Oxidative stress and its impact on skin, scalp and hair. Int J Cosmet Sci 43(1):S9-S13. https://doi.org/10.1111/ics.12736\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eSari ARP, Rufaut NW, Jones LN, Sinclair RD (2016) Characterization of ovine dermal papilla cell aggregation. Int J Trichol 8:121\u0026ndash;129. https://doi.org/10.4103/0974-7753.188966\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eSim WJ, Kim J, Baek KS et al (2024) Porcine placenta peptide inhibits UVB-induced skin wrinkle formation and dehydration: Insights into MAPK signaling pathways from in vitro and in vivo studies. Int J Mol Sci 25(1):83. https://doi.org/10.3390/ijms25010083\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eTiwary S, Shukla D, Tripathi AK et al (2006) Effect of placental-extract gel and cream on non-healing wounds. 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Exp Dermatol 29(7):588\u0026ndash;597. https://doi.org/10.1111/exd.14109\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eWilliams R, Westgate GE, Pawlus AD et al (2021) Age-related changes in female scalp dermal sheath and dermal fibroblasts: How the hair follicle environment impacts hair aging. J Invest Dermatol 141(4S):1041\u0026ndash;1051. https://doi.org/10.1016/j.jid.2020.11.009\u003c/span\u003e\u003c/li\u003e\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":false,"highlight":"","institution":"","isAcceptedByJournal":true,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"international-journal-of-peptide-research-and-therapeutics","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"ijpr","sideBox":"Learn more about [International Journal of Peptide Research and Therapeutics](http://link.springer.com/journal/10989)","snPcode":"10989","submissionUrl":"https://submission.nature.com/new-submission/10989/3","title":"International Journal of Peptide Research and Therapeutics","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"em","reportingPortfolio":"Springer Hybrid","inReviewEnabled":true,"inReviewRevisionsEnabled":false},"keywords":"Low-molecular-weight porcine placental peptides, Scalp elasticity, Hair luster, Hair tensile strength, Hair roughness","lastPublishedDoi":"10.21203/rs.3.rs-8923782/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-8923782/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003eThe aging of scalp and hair is a complex biological process characterized by reduced biomechanical elasticity and degradation of follicular support structures, resulting in altered hair physical properties and appearance. However, clinical evidence for nutritional interventions targeting these aging markers remains limited. This study investigated the effects of hydrolyzed low-molecular-weight porcine placental peptides (Placenderm\u0026reg;) on scalp elasticity and the biophysical and visible aging-related characteristics of hair. In this 24-week, randomized, double-blind, placebo-controlled, parallel-group trial, 100 adults were assigned to receive either Placenderm\u0026reg; (500 mg/day) or a placebo. Scalp elasticity (ballistometry), hair physical properties (diameter and tensile strength), hair shaft morphology and roughness (SEM and ImageJ analysis), and hair luster (SAMBA system and expert visual assessment) were evaluated at baseline and week 24. Subjective satisfaction and safety parameters were also monitored. After 24 weeks, the Placenderm\u0026reg; group demonstrated statistically significant improvements in scalp elasticity, hair diameter, and tensile strength compared with the placebo group. Scanning electron microscopy (SEM) analysis revealed a significant reduction in hair surface roughness (Ra) in the intervention group, suggesting attenuation of cuticle damage and structural degradation. In addition, hair luster scores and subjective satisfaction were significantly higher in the intervention group. No serious adverse events were reported. Oral supplementation with Placenderm\u0026reg; significantly improved scalp elasticity and hair physical and microstructural characteristics. These findings suggest that Placenderm\u0026reg; is a safe and effective nutritional intervention for mitigating age-related changes in the scalp and hair.\u003c/p\u003e","manuscriptTitle":"Improvements in scalp elasticity and hair properties following supplementation with low-molecular-weight porcine placental peptides (Placenderm®): A randomized, double-blind, placebo-controlled clinical trial","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2026-02-26 13:47:35","doi":"10.21203/rs.3.rs-8923782/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"decision","content":"Revision requested","date":"2026-03-06T12:47:00+00:00","index":"","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2026-03-04T22:26:30+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2026-02-28T21:34:50+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"71863835091483051100880007231384705321","date":"2026-02-26T19:19:07+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"72883406863781586313889010479479130483","date":"2026-02-26T18:25:09+00:00","index":"hide","fulltext":""},{"type":"reviewersInvited","content":"","date":"2026-02-24T16:33:02+00:00","index":"","fulltext":""},{"type":"editorAssigned","content":"","date":"2026-02-21T09:05:25+00:00","index":"","fulltext":""},{"type":"checksComplete","content":"","date":"2026-02-21T09:04:53+00:00","index":"","fulltext":""},{"type":"submitted","content":"International Journal of Peptide Research and Therapeutics","date":"2026-02-20T08:19:13+00:00","index":"","fulltext":""}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"international-journal-of-peptide-research-and-therapeutics","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"ijpr","sideBox":"Learn more about [International Journal of Peptide Research and Therapeutics](http://link.springer.com/journal/10989)","snPcode":"10989","submissionUrl":"https://submission.nature.com/new-submission/10989/3","title":"International Journal of Peptide Research and Therapeutics","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"em","reportingPortfolio":"Springer Hybrid","inReviewEnabled":true,"inReviewRevisionsEnabled":false}}],"origin":"","ownerIdentity":"b1814fdc-1405-496b-8b76-86b5fbf2f7a1","owner":[],"postedDate":"February 26th, 2026","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"published-in-journal","subjectAreas":[],"tags":[],"updatedAt":"2026-04-27T16:01:56+00:00","versionOfRecord":{"articleIdentity":"rs-8923782","link":"https://doi.org/10.1007/s10989-026-10823-5","journal":{"identity":"international-journal-of-peptide-research-and-therapeutics","isVorOnly":false,"title":"International Journal of Peptide Research and Therapeutics"},"publishedOn":"2026-04-21 15:57:33","publishedOnDateReadable":"April 21st, 2026"},"versionCreatedAt":"2026-02-26 13:47:35","video":"","vorDoi":"10.1007/s10989-026-10823-5","vorDoiUrl":"https://doi.org/10.1007/s10989-026-10823-5","workflowStages":[]},"version":"v1","identity":"rs-8923782","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-8923782","identity":"rs-8923782","version":["v1"]},"buildId":"XKTyCvWXoU3ODBz1xrDgd","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}