Tirzepatide and PCOS: What a 54,000-Woman Study Found

On August 19, 2026, the Journal of the Endocrine Society published the first large real-world look at how much weight women with polycystic ovary syndrome lose on tirzepatide. Until then, there was no direct answer. The phase 3 obesity trials never reported PCOS as a separate subgroup, so a woman with PCOS weighing this medication was extrapolating from results measured in everybody else.

The finding, in one line: in this cohort, the women with PCOS lost about as much as the women without it.

What the study measured

Researchers reviewed records from 54,114 women prescribed tirzepatide through Voy, a UK digital weight-management service, between February 2024 and January 2025. The paper declares no relevant external funding, but four of its authors are employees of Menwell Ltd, the company that operates Voy, the same service whose patient records and digital tools the study evaluates. Keep that in view when reading its results. Of those, 4,241 (7.84%) reported having PCOS.

Among the women with PCOS still being followed at 10 months, 40 of the 4,241, or 0.94% of that group, mean weight change was -19.40% of starting body weight (95% CI, -22.38% to -16.42%). Every percentage below describes those 40 women, in a retrospective study with no randomization, no control group and self-reported weights. The distribution:

• 96.58% had lost at least 5%
• 90.80% had lost at least 10%
• 75.96% had lost at least 15%
• 57.66% had lost at least 20%

Women without PCOS at the same point had lost a mean 18.74%. The gap between the two groups was not statistically significant (P = .68). That is the actual result here: having PCOS did not appear to blunt the response.

The authors also report that women with PCOS who used the service's digital tools lost 3.42 percentage points more than those who did not (95% CI, 1.71 to 5.12; P < .001). They flag that engagement was self-selected, so motivation rather than the tools could account for some or all of that. It is also a favourable finding about a commercial product, published by authors employed by the company that sells it, and it should carry less weight than the rest of the paper.

Read the denominator before you weigh the number

Mean follow-up across the whole cohort was 2.28 months. At the 10-month mark, only 40 women with PCOS and 397 without were still in follow-up. The 19.40% figure describes those 40 women.

This is a retrospective observational study, not a trial. There was no randomization and no control group, so it cannot establish that tirzepatide caused the loss. Weights were self-reported. PCOS status was self-reported, which means some women in the PCOS group may not have the diagnosis and some in the comparison group may have it undiagnosed. The authors state all of these limits themselves. Treat the result as a real-world signal that PCOS does not seem to change the response, not as a precise number.

How it lines up with the trial evidence

SURMOUNT-1 is the phase 3 randomized, double-blind, placebo-controlled trial of tirzepatide in 2,539 adults with obesity, or overweight with a weight-related condition, and without type 2 diabetes. It was funded and run by Eli Lilly, the manufacturer. Its posted primary result, percent change in body weight at week 72, was -16.0%, -21.4% and -22.5% across its three tirzepatide dose levels, against -2.4% on placebo. A longer follow-up of the same trial later tracked participants out to 176 weeks.

The roughly 19% observed in women with PCOS at 10 months sits inside that range. The designs are not comparable in any strict sense: different follow-up windows, a trial versus a clinical service, measured versus self-reported weight. But nothing in the real-world data points to PCOS pulling the response down.

That is consistent with how tirzepatide works. Per its FDA prescribing information, tirzepatide is a dual GIP and GLP-1 receptor agonist that acts on brain regions regulating appetite and calorie intake and delays gastric emptying. None of that runs through the pathways that define PCOS, so there was no strong mechanistic reason to expect a different answer. The study confirms rather than surprises.

The contraception question is not a footnote

If you have PCOS and could become pregnant, this is the part that matters most.

The 2023 International Evidence-based Guideline for PCOS says anti-obesity medications could be considered, alongside active lifestyle intervention, for managing higher weight in adults with PCOS. In the same section it says clinicians should ensure concurrent effective contraception when pregnancy is possible for women taking GLP-1 receptor agonists, because pregnancy safety data are lacking. The guideline also tells clinicians to discuss side effects, the high risk of weight regain after stopping, and the absence of long-term safety data.

The label adds a specific wrinkle. Because tirzepatide delays gastric emptying, women using oral hormonal contraceptives are advised to switch to a non-oral method or add a barrier method for four weeks after starting and after each dose increase. If a combined oral contraceptive is currently part of how your PCOS is managed, that interaction belongs in the conversation before anything begins, not after.

The label also carries a boxed warning: in rats, tirzepatide caused thyroid C-cell tumors, and whether that applies to humans is unknown. It is contraindicated in people with a personal or family history of medullary thyroid carcinoma or MEN 2. The most common adverse reactions are gastrointestinal: nausea in 25% to 29% of treated patients, diarrhea in 19% to 23%, constipation in 11% to 17%, vomiting in 8% to 13%.

What this means if you have PCOS

You now have a number where before there was a blank. It comes with real caveats, and 40 women is a thin foundation for a headline percentage. What the study supports is narrower and still useful: across a large cohort, PCOS did not look like a reason to expect less from tirzepatide than anyone else gets.

What it does not tell you is whether tirzepatide is appropriate for you, whether it improves the other things PCOS does (the study had limited data on reproductive and hormonal outcomes beyond weight), or what happens when you stop. That last one the guideline is blunt about: weight regain risk after discontinuation is high, and long-term safety data are not there yet.

As of August 2026, tirzepatide is approved for weight management in adults with obesity, or overweight with at least one weight-related condition, alongside a reduced-calorie diet and increased physical activity. Whether you meet that description, and whether it fits your history, is a decision for you and a licensed provider.