Efficacy of melatonin and letrozole combination therapy compared to letrozole alone in the treatment of symptomatic endometrioma in infertile women

In: International Journal of Reproduction, Contraception, Obstetrics and Gynecology · 2025 · vol. 14(9) , pp. 2853–2858 · doi:10.18203/2320-1770.ijrcog20252709 · W4413800657
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AI-generated summary by claude@2026-06, 2026-06-07

This study found that combining melatonin with letrozole offered similar pain reduction and endometrioma size decrease as letrozole alone in infertile women.

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This randomized controlled trial evaluated whether adding melatonin to letrozole improves outcomes in 40 infertile women with symptomatic endometrioma, comparing 3 months of combination therapy (letrozole 2.5 mg twice daily plus melatonin 3 mg at night) versus letrozole alone. Both groups showed significant reductions over 3 months in mean pain measured by VAS and in mean endometrioma size, but between-group comparisons found no statistically significant differences in pain score or endometrioma size reduction. The key limitation highlighted by the reported design/results is the small sample size (n=40), which may limit power to detect between-group differences. This paper is centrally about endometriosis — it tests melatonin plus letrozole for symptomatic endometrioma in infertile women.

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Abstract

Background: Endometriosis is an estrogen-driven inflammatory condition involving endometrial tissue growth outside the uterus. Letrozole, an aromatase inhibitor, lowers estrogen levels to reduce pain and lesion size. Melatonin offers additional benefits through its antioxidant, anti-inflammatory, and anti-proliferative effects on endometrial tissue. The present study was conducted to compare the effects of a combination of melatonin and letrozole with letrozole alone in infertile women with symptomatic endometrioma. Methods: This randomized controlled trial was conducted in the Department of Reproductive Endocrinology and Infertility of Bangabandhu Sheikh Mujib Medical University from July, 2023 to June, 2024. Total 40 infertile women with symptomatic endometrioma were included in this study. They were randomly allocated to receive either tab. letrozole 2.5 mg, twice daily plus tab. melatonin 3mg, 3 tablets at night daily or only tab. letrozole 2.5 mg, twice daily for 3 months. Results: Mean VAS score (6.88±2.39 vs 2.64±1.96) and mean size of endometrioma (3.77±1.22 vs 3.05±1.17 cm) were significantly decreased after 3 months of treatment with melatonin and letrozole combination therapy and mean VAS score (7.11±1.81 vs 3.22±1.89) and mean size of endometrioma (3.81±1.00 cm vs 3.27±0.85) were also significantly decreased after 3 months of treatment with letrozole alone group .But there were no statistically significant difference in terms of reducing pain score and size of endometrioma when compared between two groups. Conclusions: Melatonin and letrozole combination therapy compared to letrozole alone provide similar efficacy on symptomatic endometrioma in terms of reduction of pain score and size of endometrioma.
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Background

Endometriosis is an estrogen-driven inflammatory condition involving endometrial tissue growth outside the uterus. Letrozole, an aromatase inhibitor, lowers estrogen levels to reduce pain and lesion size. Melatonin offers additional benefits through its antioxidant, anti-inflammatory, and anti-proliferative effects on endometrial tissue. The present study was conducted to compare the effects of a combination of melatonin and letrozole with letrozole alone in infertile women with symptomatic endometrioma.

Methods

This randomized controlled trial was conducted in the Department of Reproductive Endocrinology and Infertility of Bangabandhu Sheikh Mujib Medical University from July, 2023 to June, 2024. Total 40 infertile women with symptomatic endometrioma were included in this study. They were randomly allocated to receive either tab. letrozole 2.5 mg, twice daily plus tab. melatonin 3mg, 3 tablets at night daily or only tab. letrozole 2.5 mg, twice daily for 3 months.

Results

Mean VAS score (6.88±2.39 vs 2.64±1.96) and mean size of endometrioma (3.77±1.22 vs 3.05±1.17 cm) were significantly decreased after 3 months of treatment with melatonin and letrozole combination therapy and mean VAS score (7.11±1.81 vs 3.22±1.89) and mean size of endometrioma (3.81±1.00 cm vs 3.27±0.85) were also significantly decreased after 3 months of treatment with letrozole alone group .But there were no statistically significant difference in terms of reducing pain score and size of endometrioma when compared between two groups.

Conclusions

Melatonin and letrozole combination therapy compared to letrozole alone provide similar efficacy on symptomatic endometrioma in terms of reduction of pain score and size of endometrioma. Metrics

References

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Outcome instruments

VAS-pain

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endometriosisendometriomainfertility

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