Adding tirzepatide to metformin in PCOS: first randomised results, 16 weeks
Source: Yang Z et al., Diabetes, Obesity and Metabolism, 3 June 2026 (PMID 42236268)
Summary
An open-label randomised controlled trial published in Diabetes, Obesity and Metabolism (3 June 2026) randomised 60 overweight or obese Chinese women with PCOS to metformin 1,000 mg twice daily alone, or metformin plus tirzepatide 5 mg once weekly, for 16 weeks. Weight fell by 10.4 ± 3.5 kg in the combination group versus 1.7 ± 2.5 kg with metformin alone; BMI fell by 4.12 ± 1.37 versus 0.68 ± 1.82 kg/m². Menstrual cycle recovery was significantly more frequent in the combination group (p = 0.013), as was the total pregnancy rate (p = 0.014). This is the first randomised evidence for tirzepatide specifically in PCOS, and it is small and short: 60 participants, 16 weeks, open-label (no blinding, so expectations can influence self-reported outcomes such as cycle regularity), a single Chinese centre, and a low tirzepatide dose (5 mg) compared with the 10–15 mg used in obesity trials. It does not establish long-term safety, durability after stopping, or effects on live births.
Why it matters for you
Until this trial, every claim about tirzepatide and PCOS cycles was an extrapolation from obesity studies. There is now a randomised signal that cycles improve — from one small, short, unblinded study. That is enough to discuss with an endocrinologist if weight and insulin resistance dominate your picture; it is not enough to treat tirzepatide as an established PCOS fertility treatment. Letrozole remains the first-line option for ovulation induction.