Research

Hormonal

Combining metformin with lifestyle modification (diet and exercise) results in significantly greater reductions in BMI and subcutaneous adipose tissue, and increases menstrual cycle frequency, compared to lifestyle modification alone in women with PCOS over 6 months.

If you have PCOS, combining metformin with lifestyle changes (diet and exercise) leads to better weight loss and more regular periods than lifestyle changes alone. However, metformin by itself does not help with weight loss compared to lifestyle changes. The benefit of adding metformin is primarily seen in weight management and menstrual regulation, not necessarily in improving blood sugar or lipid markers beyond what lifestyle changes achieve.

ModerateSupportsMEDIUM confidence
Lifestyle + metformin were associated with lower BMI (mean difference (MD) 20.73 kg/m2, 95% confidence intervals (CI) 21.14, 20.32, P ¼ 0.0005) and subcutaneous adipose tissue (MD 292.49 cm2, 95% CI 2164.14, 220.84, P ¼ 0.01) and increased number of menstrual cycles (MD 1.06, 95% CI 0.30, 1.82, P ¼ 0.006) after 6 months compared with lifestyle + placebo.
Negar Naderpoor et al. · Human Reproduction Update · 2015

Why this rating

Meta-analysis of 12 RCTs, but studies had small sample sizes, short durations, and varying risk of bias.

Source

Metformin and lifestyle modification in polycystic ovary syndrome: systematic review and meta-analysis

Negar Naderpoor et al. · Human Reproduction Update · 2015

DOI 10.1093/humupd/dmv025

Meta-analysis · 12 studiesCited 324×
Read the paper
DOI resolved against Crossref · corpus check 2026-06-10

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