Research

Hormonal

Metformin treatment in abdominally obese women with PCOS significantly decreases serum testosterone and leptin levels, and improves hirsutism and menstrual cycle regularity, effects not seen with placebo.

For women with PCOS, metformin (1700 mg/day) combined with diet not only aids weight loss but also specifically targets hormonal imbalances by lowering testosterone and leptin levels. This leads to tangible clinical improvements, including reduced hirsutism (excess hair growth) and more regular menstrual cycles, which are key quality-of-life factors for PCOS patients.

GoodSupportsHIGH confidence
Testosterone concentrations decreased only in PCOS women treated with metformin. Leptin levels decreased only during metformin treatment in both PCOS and control groups. In the PCOS group, metformin therapy improved hirsutism and menstrual cycles significantly more than placebo.
Renato Pasquali et al. · The Journal of Clinical Endocrinology & Metabolism · 2000

Why this rating

Same RCT design as N1, with clear statistical significance reported for testosterone, leptin, hirsutism, and menstrual frequency.

Source

Effect of Long-Term Treatment with Metformin Added to Hypocaloric Diet on Body Composition, Fat Distribution, and Androgen and Insulin Levels in Abdominally Obese Women with and without the Polycystic Ovary Syndrome

Renato Pasquali et al. · The Journal of Clinical Endocrinology & Metabolism · 2000

DOI 10.1210/jcem.85.8.6738

rct · n=40Cited 622×
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DOI resolved against Crossref · corpus check 2026-06-10

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