The Effect of Lavender on Mood Disorders Associated with the Use of Combined Oral Contraceptives (COCs): A Triple-Blinded Randomized Controlled Trial

Background: Combined oral contraceptives (COCs) are reliable medications used as a contraception method. One of the most common reasons for discontinuing COCs is their association with negative mood disorders. Studies have confirmed the anti-anxiety and mood-stabilizing effects of lavender. This study was conducted to investigate the effects of lavender essential oil (LEO) on mood disorders associated with the use of COCs. Methods: This triple-blinded clinical trial was conducted on 60 married women (aged 15-49 years old) who were consumers of COCs, referring to 26 health centers in Tabriz, Iran. The participants were randomly assigned to either the intervention (consuming one gelatin capsule containing 80 mg LEO daily) or control (consuming one placebo capsule daily) group. The intervention continued for 56 days. Scores for Positive and negative were determined using the Positive and Negative Affect Schedule (PANAS) questionnaire, and stress, depression, anxiety were measured using the DASS-21 questionnaire on day’s 28 th and 56 th post-intervention. Data analysis was conducted using the t-test and ANOVA with the RM model and a p-value of < 0.05 was considered significant for all analyses. Results: A statistically significant difference was observed in mood disorders, stress, and depression between women receiving LEO or placebo. The consumption of LEO increased the positive mood on day 28 [MD (95% CI): 4.5 (2.1 to 7.0), p=0.001] and day 56 [5.9 (3.4 to 8.3), p<0.001] while decreased the negative mood on day 28 [MD (95% CI): -3.5 (-5.3 to -1.3), p<0.001] and day 56 [-4.3 (-6.3 to -2.2), p<0.001] , stress on day 28 [MD (95% CI): -4.9 (-7.1 to -2.8), p=0.001] and day 56 [-5.3 (-7.6 to -3.1), p<0. 001], and depression on day 28 [MD (95% CI): -3.0 (-4.9 to 1.1), p=0.003] and day 56 [-3.1 (-5.0 to 1.2), p=0.002]. There was no statistically significant difference between the two groups in terms of anxiety. Conclusions: The consumption of LEO with COCs improved mood disorders and reduced stress and depression. It is expected that appropriate counseling and education should be offered to women using COCs regarding the possibility of mood changes, providing appropriate solutions, including the simultaneous use of LEO. The registration number IRCT20110606006709N24. The registration date 20/04/2022