Does Mounjaro stop the contraceptive pill working?

It may reduce how well the pill works because it slows stomach emptying. The MHRA advises using a barrier method (like condoms) or switching to a non-oral contraceptive for 4 weeks after starting and for 4 weeks after each dose increase.

How long do I need extra contraception on Mounjaro?

For 4 weeks after you start Mounjaro and for 4 weeks after every dose increase, if you rely on the oral contraceptive pill. Non-oral methods such as the implant, injection, IUD or condoms are not affected in the same way.

Can I take Mounjaro if I'm pregnant or trying to conceive?

No. Mounjaro is not recommended in pregnancy or breastfeeding, and NHS guidance advises stopping it at least one month before trying to conceive. Speak to your prescriber about planning ahead.

Mounjaro and contraception: what to know

Mounjaro can reduce how well the contraceptive pill works, and UK regulators have issued specific advice. Here's the official guidance on contraception and pregnancy.

Last updated 23 June 2026

This is one of the most important safety points for anyone who could become pregnant. Mounjaro (tirzepatide) can affect how well oral contraceptives (the pill) work, and in June 2025 the UK's medicines regulator, the MHRA, issued specific advice for women using these medicines. This is general information, not personal medical advice — discuss your contraception with your prescriber or pharmacist.

Why the pill may work less well

Mounjaro slows how quickly the stomach empties, especially in the first weeks and after a dose increase. Because of this, the manufacturer states that reduced effectiveness of oral contraceptives cannot be excluded.

What the MHRA advises

The official guidance is to either switch to a non-oral method of contraception, or add a barrier method (such as condoms):

For 4 weeks after starting Mounjaro, and
For 4 weeks after each increase in your dose.

Pregnancy and breastfeeding

Mounjaro is not recommended during pregnancy or while breastfeeding, as there isn't enough safety information. If you're planning a pregnancy, NHS guidance advises stopping Mounjaro at least one month beforehand. If you think you might be pregnant while taking it, contact your prescriber.

Frequently asked questions

Does Mounjaro stop the contraceptive pill working?: It may reduce how well the pill works because it slows stomach emptying. The MHRA advises using a barrier method (like condoms) or switching to a non-oral contraceptive for 4 weeks after starting and for 4 weeks after each dose increase.
How long do I need extra contraception on Mounjaro?: For 4 weeks after you start Mounjaro and for 4 weeks after every dose increase, if you rely on the oral contraceptive pill. Non-oral methods such as the implant, injection, IUD or condoms are not affected in the same way.
Can I take Mounjaro if I'm pregnant or trying to conceive?: No. Mounjaro is not recommended in pregnancy or breastfeeding, and NHS guidance advises stopping it at least one month before trying to conceive. Speak to your prescriber about planning ahead.

Eligibility checker Clicks calculator

Sources

Educational tool — not medical advice. This calculator is for general information only. Mounjaro (tirzepatide) is a prescription-only medicine. Always follow the dosing instructions given by your prescriber and the patient information leaflet, and never change your dose or use click-counting without professional guidance.