Accidentally got pregnant on Mounjaro: the NHS guidance and what it means for you

You've just had a positive test — here's what to do in the next 24 hours

Stop taking Mounjaro immediately. Do not wait for your next scheduled dose, do not wait for a clinic letter, and do not assume a few more days on it will be fine. Call your GP surgery today and tell the receptionist you are pregnant and have been taking tirzepatide for weight management. Most surgeries will triage this quickly. If you cannot reach your GP, NHS 111 can advise you and, where needed, arrange an urgent appointment.

One misconception worth gently clearing up: some people assume that because they felt fine on Mounjaro, continuing for a few more weeks while they sort out a plan is safe. The concern is not how you feel day to day, it is that tirzepatide's effects on a developing pregnancy are not fully understood in humans, and animal studies flagged developmental risks at high exposures. Caution is the standard for good reason.

If you are also taking other medications, mention every one of them when you speak to your GP. Your care team will want a full picture before making any recommendations about monitoring or referral. The NHS tirzepatide medicines page confirms that the medicine is not recommended in pregnancy and should be stopped if you become pregnant.

Why did this happen? The contraception link most people miss

This catches more people than you might expect, and it is not a failure of your contraception brand. Mounjaro slows gastric emptying, which can reduce how reliably the gut absorbs oral medicines, including the contraceptive pill. NHS England's guidance on weight-management injections specifically flags this: for tirzepatide, women on oral contraceptives should use an additional non-oral method, such as condoms, during the first four weeks of starting treatment and for four weeks after every dose increase.

If your dose was increased in the weeks before conception, and you were relying solely on the pill, that window is likely when pregnancy became possible. This is worth understanding not to assign blame, but because it is directly relevant to the conversation you need to have with your prescriber about contraception going forward, once your pregnancy situation is resolved.

There is no equivalent evidence of this interaction for semaglutide (the active ingredient in Wegovy), but for tirzepatide the NHS position is clear. If you have questions about your specific contraception history, your GP is the right person to talk through it with.

What happens to your weight-loss treatment now?

Mounjaro will not be appropriate during pregnancy or while breastfeeding. That is straightforward. What comes after depends entirely on your situation: how the pregnancy progresses, whether you breastfeed, and what your health needs look like postnatally.

Some people worry about weight regain after stopping. That is a real and understandable concern, and your care team can factor it into postnatal planning. It is worth knowing that restarting a weight-loss medicine after pregnancy is possible, and if you are already thinking ahead, our guide on what to consider when you want to buy Mounjaro covers the key steps so you know what to expect when the time is right. Our clinical team (you can read about our approach on our prescriber's profile) can support that planning when the time comes.

In the meantime, understanding how Mounjaro supports weight management may help you think about lifestyle strategies to carry into pregnancy. Diet quality, hydration and activity, within whatever your midwife recommends, matter whether or not any medicine is involved.

If you were on an NHS-prescribed course of Mounjaro, contact whoever manages that prescription (your GP or the specialist service) directly. For a clear overview of the criteria and process involved, our page explaining how to get a Mounjaro prescription for weight loss sets out what prescribers look for, which can help you prepare for that conversation. You can also read more about how NHS Mounjaro prescribing works to understand who your main contact should be.

When to seek help urgently, and who can help you plan what comes next

Call 999 or go to A&E if you experience severe abdominal pain, significant bleeding, or any symptom that worries you acutely. For anything less urgent, your GP is the right first port of call, followed by your midwifery team once booking is arranged.

If you were prescribed Mounjaro privately and are not sure who to contact, our support team is available seven days a week and can help you understand your next step. We do not prescribe Mounjaro in pregnancy, and we will always refer you back to your GP or midwife for clinical decisions related to pregnancy itself.

Side effects of stopping tirzepatide are generally mild; most people notice their appetite returning gradually. If you experience persistent nausea or vomiting in the early weeks after stopping, that is more likely to be early pregnancy than withdrawal, and your GP or midwife should know about it. Suspected side effects can also be reported via the MHRA Yellow Card scheme.

Once your pregnancy is complete and you are ready to think about weight management again, a private consultation remains an option, and if you were previously treated through the health service it is also worth reading about how to get Mounjaro on the NHS to understand whether that route is still open to you. If cost and access are part of your thinking, our page on buying Mounjaro through the NHS explains how NHS supply works in practice. You can explore what treatment involves at any point, with no obligation.