Mounjaro PCOS Weight Loss: Evidence and UK Eligibility
Mounjaro is not licensed specifically to treat PCOS. It may be prescribed for weight management when someone with PCOS independently meets the standard UK eligibility criteria. In a 2026 retrospective UK cohort of 4,241 women with self-reported PCOS who began tirzepatide, mean weight loss was 14.9% among 472 women still on treatment at six months and 19.4% among 40 who reached ten months. Because this was observational, self-reported completer data, it does not prove that Mounjaro directly improves PCOS symptoms, fertility or long-term outcomes.
Evidence on Mounjaro for PCOS weight loss is developing. The Mounjaro weight loss injection may be considered when a person with PCOS meets the standard weight-management criteria. This guide explains what is licensed, what the latest observational evidence found and what remains uncertain.
Mounjaro is licensed in the UK for weight management in adults who meet the eligibility criteria and separately for treating type 2 diabetes; our Mounjaro and type 2 diabetes guide explains that indication. It is not licensed specifically for PCOS. Eli Lilly states that it has not sponsored trials evaluating tirzepatide specifically in people with PCOS. People with PCOS were not explicitly excluded from its phase 3 programmes, but no dedicated PCOS subgroup analysis was performed.
What this means in practice
PCOS alone does not create a separate prescribing pathway for Mounjaro. Eligibility is assessed against the standard UK criteria for weight management or type 2 diabetes. If treatment is prescribed, the usual Mounjaro dose schedule applies, with dose changes based on response and tolerability.
PCOS is associated with insulin resistance and a higher risk of excess weight, while excess weight can worsen insulin resistance and some PCOS symptoms. This can make weight management more difficult. For people living with overweight or obesity, sustainable weight loss is commonly recommended as part of PCOS care alongside individual advice on diet, activity, fertility and other treatments.
There is still no large randomised trial designed to test tirzepatide specifically as a PCOS treatment. The strongest PCOS-specific weight-loss evidence currently available is a 2026 retrospective UK cohort published in the Journal of the Endocrine Society. Semaglutide has a separate evidence base, so Wegovy for PCOS should be considered on its own rather than used to predict results with tirzepatide.
2026 UK Observational Study
The study included 54,114 women who started tirzepatide through an online weight-management programme, including 4,241 who self-reported PCOS. Among the 472 women with PCOS who remained in the dataset at six months, mean weight loss was 14.91%. Among the 40 who reached ten months, mean weight loss was 19.40%. Weight-loss outcomes were not significantly different from those recorded in women without PCOS.
What the Study Cannot Tell Us
This was an observational study rather than a randomised controlled trial. PCOS status was self-reported, and the longer-term result came from only 40 women who completed ten months of treatment. The study focused on weight change; it did not establish whether tirzepatide improves ovulation, fertility, androgen-related symptoms or long-term PCOS outcomes.
Important context
The findings suggest that women with PCOS can lose weight with tirzepatide at a similar rate to women without PCOS. They do not prove that Mounjaro treats PCOS itself, and treatment still requires an individual eligibility and safety assessment.
- Clinically meaningful weight loss when treatment is suitable and supported by sustainable lifestyle changes
- Possible improvement in insulin sensitivity as weight falls, although individual results vary
- Possible secondary improvement in some PCOS symptoms, which has not yet been confirmed in large PCOS-specific trials
Mounjaro is not a hormonal treatment for PCOS. Any wider benefit is expected to arise mainly through weight loss and metabolic change, so symptom response should be reviewed separately with the clinician managing your PCOS.
PCOS treatment depends on the symptoms and priorities that matter to you. Options may include lifestyle support, metformin, hormonal contraception, fertility treatment or medicines for androgen-related symptoms. Mounjaro does not replace these treatments and has not been directly compared with them in a large PCOS-specific randomised trial. A clinician should consider weight management alongside menstrual health, fertility plans, metabolic risk and any other treatment you use.
PCOS and menopause are different conditions, but some women manage both later in life. If menopause-related weight gain or HRT is also relevant, our Mounjaro for menopause guide covers those separate considerations.
A Combined Approach Often Works BestWhen Mounjaro is prescribed for weight management, it should sit within a wider plan that includes sustainable eating, regular activity and clinical review. Our Mounjaro nutrition guide explains how to build balanced meals and manage reduced appetite while using treatment. Your PCOS care may also need separate review rather than relying on weight change alone.
Pregnancy and ContraceptionMounjaro should not be used during pregnancy. The UK prescribing information advises stopping tirzepatide at least one month before a planned pregnancy. If you are trying to conceive, discuss this before starting treatment so your prescriber can recommend an appropriate plan.
For women with overweight or obesity who use an oral contraceptive, the UK prescribing information advises switching to a non-oral method or adding a barrier method for four weeks after starting Mounjaro and for four weeks after every dose increase. Ask your prescriber or pharmacist which option is suitable for you. For a fuller explanation of which methods are affected and when extra protection is needed, read our Mounjaro and the contraceptive pill guide.
Discuss Your Full Health Picture With Our Team
Our GPhC-registered pharmacy team can talk through your eligibility for Mounjaro, including how PCOS and related insulin resistance fit into your overall assessment.
Start Your Free Online Consultation → Happy Pharmacy is a GPhC-registered pharmacy (No. 9013192) — Superintendent Pharmacist: Palvinder Deol- Weight loss outcomes with tirzepatide in women with and without self-reported polycystic ovary syndrome. Journal of the Endocrine Society, 2026.
- Role of Tirzepatide in Obesity Management Among Women with Polycystic Ovary Syndrome. Retrospective observational study.
- Has Mounjaro® (tirzepatide) been studied in patients with polycystic ovary syndrome (PCOS)? Eli Lilly and Company, medical.lilly.com.
- The Potential Utility of Tirzepatide for the Management of Polycystic Ovary Syndrome. PMC, National Institutes of Health.
- NHS. Polycystic ovary syndrome (PCOS): overview, symptoms and treatment.
- Mounjaro® (tirzepatide) UK Summary of Product Characteristics.