Summary: In an open-label trial in overweight and obese women with PCOS, combining metformin and liraglutide reduced weight, visceral fat, and free testosterone more than metformin alone over 12 weeks, with a parallel rat study suggesting a gut-microbiota mechanism.
PICO Summary
| Element | Detail |
|---|---|
| Population | 60 overweight/obese women with PCOS (20 per group), plus a parallel letrozole-induced PCOS rat study; open-label randomised controlled trial, China. |
| Intervention | Combination metformin 0.85 g twice daily plus liraglutide 1.2 mg daily (COM group) for 12 weeks. |
| Comparison | Metformin alone or liraglutide alone at the same doses. |
| Outcome | All groups reduced weight, glucose, lipids, and LH/FSH ratio. The combination reduced body weight, BMI, visceral fat area, and body-fat percentage more than metformin alone (p<0.05), and reduced free testosterone more than metformin alone (p=0.01). In rats, the combination improved estrous cycling and ovarian morphology and favourably altered gut-microbiota diversity. |
Metformin + liraglutide in PCOS
Open-label RCT · overweight/obese PCOS · 12 weeks
Over 12 weeks, adding liraglutide to metformin lowered free testosterone, body weight, BMI, visceral fat, and body-fat percentage significantly more than metformin alone in overweight or obese women with PCOS. The trial was open-label with 20 women per arm, so the effect is promising but not definitive.
Expert Commentary
This is a sensible translational study pairing a clinical trial with mechanistic animal work, and its logic is sound, since metformin improves insulin sensitivity while a GLP-1 receptor agonist drives weight loss and incretin effects, so additive benefit on the weight-driven hyperandrogenism of PCOS is plausible and is what the combination delivered, including a greater fall in free testosterone that targets a core feature of the syndrome. The rat microbiome data add a coherent mechanistic thread consistent with growing interest in gut dysbiosis in PCOS. Two limitations deserve emphasis beyond the obvious short duration. First, the clinical trial was open-label, without blinding or placebo, which can inflate apparent benefit, particularly for weight and adherence-sensitive outcomes. Second, with 20 women per arm it is modest, fertility and menstrual outcomes were not directly reported, and the liraglutide dose was lower than the 3.0 mg used for obesity. Cost is also material. Can I use this with my patients? Yes, in line with emerging practice and with candour. For an overweight woman with PCOS responding inadequately to metformin, adding a GLP-1 agonist is a reasonable, mechanistically complementary step, with gradual titration for gastrointestinal tolerability, while I frame the evidence as promising but open-label and short, and do not promise fertility benefit.
References
Long XF, Fang YQ, Li YH, et al. Combination metformin and liraglutide in PCOS: clinical efficacy in women and preclinical insights from gut microbiome modulation in rats. Front Endocrinol (Lausanne). 2025;16:1599879. doi:10.3389/fendo.2025.1599879