What is PCOS?
Polycystic ovary syndrome — PCOS — is the most common hormonal disorder in women of reproductive age, affecting approximately 8–13% of all women. It is one of the leading causes of reduced fertility. Despite the name, PCOS is not just about the ovaries — it is a complex metabolic condition that affects the whole body.
The three hallmarks of PCOS are:
- Irregular or absent ovulation — causing unpredictable or absent periods
- Elevated male sex hormones (androgens) — which can cause excess facial hair, acne, and scalp hair thinning
- Polycystic ovaries — many small follicles clustered on the ovary surface, visible on ultrasound
For many women with PCOS, the underlying engine is insulin resistance — the body's cells do not respond normally to insulin. This pushes the body to produce more insulin, which in turn stimulates the ovaries to make excess androgens. This is exactly where GLP-1 medications become relevant.
What is GLP-1 — and what does it do?
GLP-1 (glucagon-like peptide-1) is a natural gut hormone released after eating. It signals the pancreas to produce insulin, reduces appetite, and blunts blood sugar spikes after meals. Medications like semaglutide (Wegovy, Ozempic) and tirzepatide (Mounjaro) mimic and amplify this hormonal signal.
This makes GLP-1 medications relevant for PCOS for two reasons: they directly lower insulin levels, and they promote weight loss — and weight loss itself improves insulin sensitivity. It is like attacking PCOS from two angles at once.
What does the research show?
Research into GLP-1 medications and PCOS is still relatively new, but the results are promising. A 2023 clinical study published in the Journal of Clinical Medicine treated obese women with PCOS who had not responded adequately to lifestyle changes with semaglutide 0.5 mg weekly. After 6 months:
- 80% experienced normalisation of their menstrual cycle
- Average weight loss of 11.5 kg, with BMI dropping from 34.4 to 29.4
- Significant improvements in insulin resistance and blood glucose levels
- Very few side effects reported
A randomised controlled trial from 2025 compared metformin alone with a combination of metformin and semaglutide in overweight/obese women with PCOS. The combination group achieved significantly greater weight loss, improved insulin sensitivity, lower inflammatory markers, menstrual normalisation — and higher natural pregnancy rates.
A 2024 review concluded that all three classes of incretin mimetics — GLP-1 agonists, dual agonists (GLP-1/GIP), and triple agonists — showed significant improvements in weight loss and insulin sensitivity compared with traditional PCOS management.
What happens to hormones?
One of the most interesting effects is the reduction in androgen levels. As insulin levels fall, the ovaries produce fewer male sex hormones. This can mean:
- Reduced unwanted hair growth (hirsutism)
- Improved acne
- Better regulation of the menstrual cycle
- Increased chance of spontaneous ovulation
It is important to note that the effect is not the same for everyone. Women with predominantly insulin-resistant PCOS tend to benefit the most, while the effect may be more limited in women with a lean PCOS phenotype.
What about fertility?
PCOS is one of the most common causes of infertility, because irregular ovulation makes it difficult to conceive. The improvement in insulin sensitivity and normalisation of the menstrual cycle can in itself increase the chances of pregnancy.
However, there is an important safety rule: semaglutide is not recommended during pregnancy. The manufacturer Novo Nordisk advises stopping semaglutide at least 2 months (8 weeks) before attempting to conceive. For tirzepatide (Mounjaro), the recommendation is at least 1 month (4 weeks) before trying. Animal studies have shown a risk of foetal malformations when used during pregnancy.
If you are on GLP-1 medication and planning a pregnancy, it is essential to discuss this with your doctor well in advance. Treatment with metformin or ovulation induction may be more appropriate when pregnancy is the immediate goal.
Is GLP-1 medication approved for PCOS?
Neither semaglutide nor tirzepatide is officially approved for the treatment of PCOS in the EU, UK, or USA. They are approved for type 2 diabetes (Ozempic, Mounjaro) and obesity (Wegovy). Use for PCOS is therefore off-label — outside the approved indications.
However, many endocrinologists and gynaecologists have begun offering these medications to women with PCOS and severe insulin resistance or obesity, as the evidence is promising. Traditional PCOS treatment with metformin and the contraceptive pill does not always adequately address the underlying insulin resistance.
Practical considerations
If you are considering GLP-1 medication as part of PCOS treatment, here are the key points to discuss with your doctor:
- Blood tests: Have fasting insulin, blood glucose (HbA1c), SHBG, and testosterone measured — this helps determine whether you have insulin-resistant PCOS.
- Weight status: The evidence is strongest for women with a BMI above 27–30. It is not impossible at lower BMI, but the evidence is more limited.
- Combining with metformin: The combination of semaglutide and metformin showed better outcomes than metformin alone in the above-mentioned trial.
- Pregnancy plans: Tell your doctor if you are considering pregnancy within the next 1–2 years.
- Side effects: Nausea and gastrointestinal discomfort are the most common side effects, but they typically ease after the first few weeks. Always start low and titrate gradually.
What to expect
Based on the available studies, here is what is realistic to expect from semaglutide treatment for PCOS:
- The first signs of improvement (more regular periods, reduced appetite) are typically seen within the first 1–3 months.
- Full effect on the menstrual cycle and insulin resistance takes 3–6 months.
- Weight loss contributes further to hormonal improvement — the more weight lost, the greater the hormonal benefit.
- Effects are maintained as long as the medication is continued. If you stop, PCOS symptoms are likely to return over time.
Conclusion
GLP-1 medications are not a cure for PCOS, but they represent a promising treatment option for women with insulin-resistant PCOS and excess weight. The dual effect — direct improvement of insulin sensitivity and weight loss — precisely targets the central drivers of many PCOS symptoms. Research suggests that up to 8 in 10 women with obesity and PCOS can normalise their menstrual cycle with semaglutide.
Always talk to your doctor or gynaecologist before starting GLP-1 treatment for PCOS — and plan carefully if pregnancy is a goal.
Sources
- Forni et al. (2023): Semaglutide Treatment of Excessive Body Weight in Obese PCOS Patients — PMC/NIH
- Metformin + semaglutide randomised controlled trial in PCOS (2025) — PMC/NIH
- GLP-1 Receptor Agonists and PCOS: A Scoping Review — PubMed/NIH
- Endocrine and metabolic effects of GLP-1 receptor agonists on women with PCOS — PMC/NIH
- The Potential Utility of Tirzepatide for PCOS — PMC/NIH