Mounjaro and Fertility in Women: What the Evidence Says (October 2026)

01 · The core answer

Does Mounjaro make women more fertile?

Mounjaro does not act directly on the ovaries or on fertility. What can change is the biology around it. Excess weight and insulin resistance can disrupt regular ovulation, and weight loss is a first-line recommendation for many women with PCOS for exactly that reason.

Weight loss itself is a first-line recommendation that can improve insulin resistance, cycles and symptoms, and improving weight can restore ovulation. So some women notice that periods become more regular. That is a possible knock-on effect, not a promise, and it is the reason an unplanned pregnancy is possible for someone who previously found conception difficult.

02 · Your decision

Which situation are you in?

The right step depends on where you are with pregnancy plans. Use this table as a starting point, then talk to a prescriber about your own circumstances.

If you meet the licensed criteria and are not planning a pregnancy soon, you can start with our Mounjaro pen consultation. You can also browse our wider weight loss clinic for other options.

Related guides: Does mounjaro affect fertility in women and Best multivitamins for women on mounjaro.

03 · Weight, PCOS and ovulation

Weight, PCOS and ovulation

Mounjaro is not licensed specifically for PCOS, but many women with PCOS meet the licensed weight-management criteria. Eligibility is assessed on the standard BMI criteria, and PCOS does not change those thresholds.¹

Why does weight matter for ovulation? When weight falls and the body responds better to insulin, cycles can become more predictable.

The medicine itself works by activating two gut-hormone pathways. Tirzepatide is the first treatment of its kind to activate two natural gut-hormone receptors at once: GIP and GLP-1.¹ Together these help regulate appetite, slow how quickly the stomach empties, and improve the way the body responds to insulin.¹

In the SURMOUNT-1 trial of 2,539 adults, people taking tirzepatide alongside diet and exercise lost on average 15% of their body weight on 5mg, 19.5% on 10mg and 20.9% on 15mg over 72 weeks, compared with 3.1% with lifestyle changes alone.² These are trial averages and individual results vary. The trial did not measure fertility, so these figures should not be read as a fertility outcome.

04 · Pregnancy and stopping

Pregnancy and stopping Mounjaro

Mounjaro must not be used during pregnancy, and it should be stopped at least one month before trying to conceive.¹ This applies whether you are planning a pregnancy or have just found out you are expecting.

If you become pregnant during treatment, stop the medicine and tell your prescriber promptly.¹³

Planning ahead makes this easier. Tirzepatide has a half-life of about five days, so after a final dose it takes roughly 4–5 weeks to clear the system, and there is no way to speed this up. Nothing needs doing while it clears.¹ Think of the stopping window as time for your body and your plans to line up, not as something you can shorten.

If you are weighing whether to start now or wait until after a pregnancy, say so in your consultation. A prescriber can talk through timing with you. Our page on Mounjaro for women covers the wider picture of treatment for women, and the male fertility guide explains how this differs for partners.

05 · Contraception on treatment

Contraception while you are on Mounjaro

The contraceptive pill is the one method with a specific interaction. Mounjaro slows stomach emptying, which can reduce how well oral contraceptive pills are absorbed.¹ The SmPC advises switching to a non-oral method, or adding a barrier method (such as condoms), for 4 weeks after starting Mounjaro and for 4 weeks after each dose increase.¹

This applies to the pill only. Implants, coils and injections are unaffected.¹ The MHRA has also issued guidance on contraception with GLP-1 and GIP medicines, which is worth reading if you rely on oral contraception.⁷

Many women find a non-oral method simpler than remembering to add condoms at every step. Your prescriber or GP can talk through the options.

Remember also that cycles can change as weight changes. Irregular or absent periods before treatment do not mean you cannot conceive, so do not treat them as contraception.

06 · Planning a pregnancy

Planning a pregnancy around weight loss

Some women start treatment hoping that weight loss will improve their chances of conceiving later. That is a reasonable plan, as long as the sequence is clear: lose weight, stop treatment well before trying, then conceive. Mounjaro itself is never part of the conception phase.

Because tirzepatide takes about four to five weeks to clear, and because the SmPC advises stopping at least a month before trying, build a gap into your timeline rather than stopping and trying on the same day.¹ It is also sensible to speak to your GP or a fertility clinic before you stop, so that any assessment or treatment can be lined up.

Questions such as whether IVF is available at a higher weight, or how diabetes affects pregnancy, depend on local clinic policy and your individual health. Ask your GP, diabetes team or fertility clinic, who can look at your history.

On the NHS, Mounjaro is available but access is being phased in over several years. NICE recommends it for adults with a BMI of at least 35 plus at least one weight-related condition, and the primary-care rollout began in June 2025 with the highest-need groups first.⁴ Full rollout is expected to take years, which is why many people choose regulated private treatment rather than waiting.⁶ The NHS guide to tirzepatide is a useful independent read too.⁵

07 · Supporting your health

Looking after yourself on treatment

Mounjaro is used alongside a reduced-calorie diet and increased physical activity.¹ If you may become pregnant in future, nutrition matters too. Our guides to the best multivitamin for women on Mounjaro and the wider benefits of Mounjaro for women are good places to continue.

If you notice any unexpected symptom, including changes to your cycle that worry you, tell your prescriber. You can also report suspected side effects through the MHRA Yellow Card scheme.¹⁹ Serious side effects are uncommon but need urgent attention. Seek immediate medical help for: severe, persistent stomach pain that may spread to your back, with or without vomiting (possible pancreatitis); pain in the upper right abdomen, fever or yellowing of skin/eyes (possible gallbladder problems); or signs of a severe allergic reaction such as swelling of the face or throat and difficulty breathing.

When you order with us, the consultation is free and reviewed by a GPhC-registered prescriber, and unsuitable orders are refunded automatically. Ongoing monthly reviews are included, so you have a route to raise pregnancy plans as they develop. Repeat orders re-check suitability and there is no auto-shipping, which makes it easy to pause if your plans change.

Our pharmacy is registered with the GPhC (9012878). Mounjaro is supplied through official LillyDirect supply, and delivery is free next-day tracked, with same-day dispatch when ordered by 3pm.