GLP-1 Medication and PCOS

There is growing interest in using GLP-1 medicines such as Mounjaro (tirzepatide) and Wegovy (semaglutide) for people with polycystic ovary syndrome (PCOS), which was renamed polyendocrine metabolic ovarian syndrome (PMOS) in 2026. These medicines are not licensed to treat PCOS itself, but people with PCOS who meet the UK criteria for weight-management treatment may be prescribed them for that purpose. Small studies suggest weight loss on GLP-1 medicines may improve some features of PCOS, such as menstrual regularity and insulin resistance, but international guidance describes the evidence as limited. Fertility may improve with weight loss, and the contraceptive pill may be less reliable on Mounjaro, so contraception and pregnancy planning are especially important.

What is PCOS (now PMOS)?

In May 2026, following a global consensus process published in The Lancet, polycystic ovary syndrome was renamed polyendocrine metabolic ovarian syndrome (PMOS). The new name is intended to reflect that the condition is a lifelong hormonal and metabolic disorder affecting several body systems, not just a condition of ovarian cysts. The change is being phased in over several years, so you will still see "PCOS" widely used. The NHS website now uses PMOS.

PCOS is common. It is estimated to affect around 1 in 10 women of reproductive age, and many people with the condition are thought to be undiagnosed.

Symptoms

The NHS lists the main symptoms as:

• Irregular periods or long gaps between periods
• Excessive hair growth (hirsutism) or hair loss
• Weight gain or difficulty losing weight
• Difficulty getting pregnant
• Mental health problems, such as depression or anxiety
• Oily skin and acne
• Feeling very tired
• Thick, dark patches of skin on the neck or armpits (acanthosis nigricans)

Why weight and insulin matter

The NHS notes that the cause is unknown but may involve hormones such as insulin and testosterone not working properly. Many people with PCOS have insulin resistance, meaning the body needs to produce more insulin to keep blood sugar normal. High insulin levels can increase testosterone production by the ovaries, which contributes to irregular periods, hirsutism and acne. Insulin resistance also makes weight gain more likely and weight loss harder.

PCOS increases the risk of type 2 diabetes, high blood pressure, cardiovascular disease, fatty liver disease and womb cancer. The NHS advises regular check-ups to help reduce these risks.

How GLP-1 medicines might help in PCOS

GLP-1 medicines reduce appetite, slow stomach emptying and improve how the body handles glucose. In people with PCOS, the potential benefits are thought to come mainly from:

• Weight loss. International guidance has long recognised that even modest weight loss can improve metabolic and reproductive features of PCOS in people with higher weight.
• Improved insulin sensitivity. Lower insulin levels may reduce ovarian testosterone production.
• Metabolic risk reduction. Effects on blood sugar, blood pressure and blood fats may help reduce long-term risks.

Tirzepatide also acts on GIP receptors. Whether this offers additional benefits specifically in PCOS has not been established.

What does the evidence show?

Clinical studies

Most published studies of GLP-1 medicines in PCOS have been small and relatively short. They have mainly used older medicines such as liraglutide and exenatide, with some studies of semaglutide. Findings across these studies have included:

• Weight loss greater than with placebo or lifestyle measures alone
• Improvements in insulin resistance
• In some studies, more regular menstrual cycles
• In some studies, reductions in testosterone levels

Evidence on outcomes that matter most to many people with PCOS, such as hirsutism, acne, live birth rates and long-term health, is limited. Large trials of tirzepatide and semaglutide specifically in PCOS were not available to inform guidance at the time of the 2023 international guideline. Check for newer evidence, as research in this area is moving quickly.

International guidance

The 2023 International Evidence-based Guideline for the Assessment and Management of PCOS, led by Monash University with international partners, reviewed anti-obesity medicines. It found that GLP-1 receptor agonists such as liraglutide and semaglutide appeared superior to placebo for weight-related outcomes in PCOS, but that the overall evidence was very limited. The guideline supports considering anti-obesity medicines, alongside lifestyle support, for adults with PCOS and higher weight, in line with general population recommendations. It also highlights the need for effective contraception when these medicines are used.

Who can be prescribed a GLP-1 with PCOS?

There is no PCOS-specific route to GLP-1 treatment in the UK. Eligibility depends on the licensed weight-management indication and, for NHS treatment, on NICE guidance.

Lower BMI thresholds are often used for people from South Asian, Chinese, other Asian, Middle Eastern, Black African or African-Caribbean backgrounds, because of a higher risk of weight-related conditions at lower BMI. The NHS notes that PCOS is more likely in people from an Asian background. Our guide to BMI thresholds and ethnicity explains this, and who can get weight-loss injections covers eligibility more broadly.

Whether PCOS counts as a weight-related condition for licensing purposes is a judgement for the prescriber. Conditions such as prediabetes, type 2 diabetes, high blood pressure and abnormal blood fats, which are common in PCOS, are listed examples in the SmPCs.

GLP-1 medicines compared with other PCOS treatments

Treatments are often combined. Your GP or specialist will tailor the approach to your symptoms and goals.

Contraception: an important consideration

Contraception is particularly relevant for people with PCOS on GLP-1 medicines, for three reasons.

1. Fertility may increase

Weight loss can restore ovulation in people with PCOS whose cycles were irregular. Some people who previously had difficulty conceiving find they become fertile again. GLP-1 medicines should not be used in pregnancy, so the MHRA advises effective contraception for everyone of childbearing potential taking them.

2. Mounjaro and the pill

Many people with PCOS take the combined pill to regulate periods or reduce hirsutism and acne. The UK Mounjaro SmPC states that reduced effectiveness of oral contraceptives cannot be excluded in women with obesity or overweight. It advises switching to a non-oral method, or adding a barrier method such as condoms for four weeks after starting tirzepatide and for four weeks after each dose increase. The MHRA highlighted this in June 2025. This advice does not apply in the same way to semaglutide or liraglutide.

If you take the pill mainly for PCOS symptoms rather than contraception, it may still be affected. Talk to your GP about whether to continue it, add protection, or use another method, such as a hormonal coil, which also helps protect the womb lining.

3. Spironolactone

Spironolactone, sometimes used for excess hair growth, should not be taken during pregnancy, which adds to the importance of reliable contraception.

Read more in our guide to Mounjaro, GLP-1s and contraception.

Planning a pregnancy with PCOS

If you want to conceive, weight loss before pregnancy may improve your chance of ovulating and may reduce some pregnancy risks. NICE's fertility guideline advises that women with a BMI over 30 who are not ovulating should be informed that losing weight is likely to increase their chance of conception.

However:

• Stop your GLP-1 in good time. Tirzepatide at least one month and semaglutide at least two months before trying to conceive, according to the MHRA and SmPCs.
• Keep using contraception during the wash-out period.
• Expect appetite to return and plan for some possible weight regain.
• Coordinate care if you are having fertility treatment, as timing must be planned with your fertility team.
• Take folic acid before conception. Those with a BMI of 30 or more may need a higher prescribed dose.

See our guide to GLP-1 medication, pregnancy and fertility for more detail.

Side effects and safety

People with PCOS experience the same potential side effects as anyone else taking GLP-1 medicines. The most common are digestive: nausea, diarrhoea, constipation, vomiting, indigestion and burping. Less common but more serious risks include gallbladder problems and acute pancreatitis. In January 2026, the MHRA strengthened warnings about acute pancreatitis across all GLP-1 medicines.

Some considerations are particularly relevant in PCOS:

• Mental health and eating. Depression, anxiety and disordered eating are more common in PCOS. GLP-1 weight-loss medicines are not appropriate for people with active eating disorders. Tell your prescriber about any history. See our guide to GLP-1 medication and mental health.
• Hair loss. Hair loss is a common side effect of Mounjaro and Wegovy in weight-management trials. Some people with PCOS already experience hair thinning, so it is worth discussing.
• Type 2 diabetes. If you have PCOS and type 2 diabetes, your diabetes medicines may need adjusting. See our guide to GLP-1 medication and type 2 diabetes.

Living well with PCOS on GLP-1 treatment

GLP-1 medicines are intended to be used as part of a wider plan. The NHS recommends a healthy, balanced diet, regular exercise and weight loss if you are overweight as core steps for managing PCOS, and these remain important on treatment.

• Prioritise protein and fibre. With a smaller appetite, it is easy to fall short on protein, which helps preserve muscle. Fibre-rich foods support digestion and blood sugar control. Our guides to protein on GLP-1 medication and what to eat on GLP-1 medication offer practical ideas.
• Build strength. Resistance exercise helps maintain muscle during weight loss and improves insulin sensitivity, which is particularly relevant in PCOS. See preserving muscle on GLP-1 medication.
• Look after sleep. Poor sleep can worsen appetite regulation and insulin resistance. Obstructive sleep apnoea is more common in people with higher weight; mention snoring or daytime sleepiness to your GP.
• Track more than weight. Keeping a record of your periods, skin, hair, energy and mood can show changes the scales miss. Our guide to measuring progress beyond the scales has ideas.
• Keep up health checks. People with PCOS are advised to have regular checks of blood pressure, blood sugar and cholesterol, whether or not they take a GLP-1.

Myths and facts

Stopping treatment

There is good evidence from trials in the general population that weight is often regained after stopping GLP-1 medicines. People with PCOS may find that symptoms such as irregular periods return if weight is regained. Planning long-term care, including lifestyle support and other PCOS treatments, is important. Our guide to weight regain after stopping GLP-1 medication explains the evidence.

Questions to ask your GP or prescriber

• Am I eligible for weight-management treatment, and is a GLP-1 appropriate for me?
• Which of my PCOS symptoms might improve with weight loss, and which need other treatments?
• How will this affect my contraception, especially if I take the pill?
• What should I do if I decide I want to try for a baby?
• Should I keep taking metformin or other PCOS medicines alongside a GLP-1?
• How will we monitor my blood sugar, blood pressure and cholesterol?

Finding the right support

PCOS care often involves several professionals, including GPs, gynaecologists, endocrinologists, dietitians and fertility specialists. If you are considering private weight-management treatment, choose a regulated provider that asks about your PCOS, contraception and pregnancy plans, and shares information with your GP. Our provider comparison sets out the medical checks each service carries out, and our prices page explains what affects the cost of private treatment. We do not rank providers, and the decision to prescribe belongs to a prescriber.

For more background, see our hubs on weight-loss injections and Mounjaro.

Reporting side effects

If you experience a suspected side effect from a GLP-1 medicine, you can report it via the MHRA Yellow Card scheme, online or using the app. Reports help the MHRA monitor safety in real-world use, including in groups such as people with PCOS.

When to speak to a professional

See your GP if:

• You think you may have PCOS (PMOS) or your symptoms are affecting daily life
• You are considering GLP-1 treatment and want to understand how it fits with your other PCOS care
• You take the pill and are starting or increasing Mounjaro
• You are planning a pregnancy

Contact your GP or prescriber promptly if:

• You think you might be pregnant while taking a GLP-1. Stop the medicine and take a pregnancy test.
• You have had unprotected sex or think your contraception has failed. Emergency contraception is more effective the sooner it is used.
• Your mood is low, or you are worrying excessively about food, weight or your body

Call NHS 111 or get urgent advice if:

• You have signs of dehydration, such as dark urine, peeing less often, dizziness or a dry mouth
• You cannot keep fluids down

Call 999 or go to A&E if:

• You have severe, persistent abdominal pain, especially if it spreads to your back, with or without vomiting, which may be pancreatitis
• You have yellowing of the skin or the whites of the eyes (jaundice), especially with pain or fever
• You are pregnant and have heavy bleeding, severe tummy pain, or one-sided pain with shoulder tip pain or dizziness

If you are struggling with your mental health or having thoughts of suicide, call NHS 111 (option 2 for mental health in many areas), contact Samaritans free on 116 123, or call 999 in an emergency.