Mounjaro and Contraception or HRT

Important: Important

Please read the information below carefully if you are using both Mounjaro and a Contraceptive or HRT. If you feel this applies to you or would like to discuss further, please contact the surgery.

What are GLP-1 Agonists?

GLP-1 agonists are medicines like tirzepatide and semaglutide. They might have other brand names too. These medicines can only be given by a doctor or nurse. They are used for people with type 2 diabetes or to help with losing weight. They work by making food leave the stomach more slowly.

 

Medication Brand Name Examples
Tirzepatide Mounjaro
Semaglutide Ozempic, Wegovy, Rybelsus
Exenatide Bydureon BCise
Liraglutide Saxenda, Diavic, Victoza
Dulaglutide Trulicity
Lixisenatide Contained in Suliqua

 

I am taking the pill. Will using a GLP-1 agonist affect my contraception?

This depends on the type of GLP-1 agonist that you are using.

If you are using tirzepatide (Mounjaro), you should use condoms along with your pill for four weeks after you start the medicine and for four weeks after any dose increase. This is because tirzepatide works a bit differently from other similar medicines. You might also think about using a different type of contraception that isn’t a pill while on tirzepatide.

For other medicines like semaglutide, exenatide, liraglutide, dulaglutide, or lixisenatide, there is no proof that they make the pill less effective.

I have diarrhoea and vomiting with my GLP-1 agonist, and I take the contraceptive pill, what should I do?

Diarrhoea and vomiting can happen when taking GLP-1 agonists and might make the pill less effective. If you vomit within three hours of taking your pill, or have bad diarrhoea for more than a day, follow the guidance for missed pills. If diarrhoea or vomiting continues, think about using a different type of contraception that isn’t a pill, or use condoms as well.

What about non-oral methods of contraception e.g. the coil, implant, injection, patch or ring, could these be affected by GLP-1 agonists?

GLP-1 agonists do not affect contraception methods that aren’t pills. So, it’s safe to use these other options without any extra precautions when taking a GLP-1 agonist.

I am planning to switch from one type/brand of GLP-1 to another, does the contraception advice remain the same?

If you are changing to tirzepatide (Mounjaro) from any other GLP-1 agonist, use condoms for four weeks after switching and for four weeks after any dose increase. Keep taking your pill too. Or, you might want to switch to a different type of contraception that isn’t a pill while using tirzepatide.

I need emergency contraception and I’m taking a GLP-1 agonist; will it work?

We don’t know yet if GLP-1 agonists affect emergency contraception pills. The copper IUD (coil) is the best emergency contraception and isn’t affected by diarrhoea or vomiting. If you need emergency contraception, tell your healthcare provider about all the medicines you’re taking, including GLP-1 agonists.

Can I take a GLP-1 agonist during pregnancy?

It’s important to use good contraception when taking a GLP-1 agonist because these medicines shouldn’t be used if you’re pregnant. If you get pregnant while on these medicines, talk to your doctor. You should also stop taking GLP-1 agonists several weeks before trying to get pregnant. The table below shows how many weeks you should stop the medicine before planning a pregnancy for some GLP-1 agonists.

Medicine Time to stop before planning a pregnancy
Tirzepatide (Mounjaro) One month
Semaglutide (Ozempic, Wegovy, Rybelsus) Two months
Exenatide (Bydureon BCise) 12 weeks

 

I’m on HRT and taking Mounjaro – what do I need to know?

If you are taking oral progestogen as part of your HRT (for example Utrogestan, Norethisterone, Medroxyprogesterone), then you need to be aware that tirzepatide (Mounjaro) may have an impact on the effectiveness of your HRT. This means your HRT might not protect your endometrium (womb lining) enough.

Please submit an Anima form to book an HRT review, as we may need to increase your dose or change you to a different form of medication.

If you do not take any component of HRT orally (for example, you use a patch, a gel, or a Mirena coil instead of a tablet) then you do not need to worry.

This patient information is based on a leaflet from the Faculty of Sexual and Reproductive Healthcare (FSRH) and the Primary Care Women’s Health Society.

This is for information only and should not be a substitute for seeking medical advice. Decisions regarding your contraception choices should always include discussion with a healthcare professional, particularly if you have any questions or concerns. No contraception is 100% effective and there is always a risk of pregnancy. The Faculty of Sexual and Reproductive Healthcare bears no liability for the choices an individual makes regarding contraception or the outcome of their decision.

 

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Page last reviewed: 12 August 2025
Page created: 11 August 2025