If you are currently using Mounjaro alongside a contraceptive pill or oral HRT, please read the following information carefully. If you feel this applies to you or you have any concerns, please reach out to us via SystmConnect so we can support you.
Many of our patients now use medications like Tirzepatide (Mounjaro) or Semaglutide (Ozempic, Wegovy) for diabetes or weight loss. These treatments work partly by slowing your stomach’s emptying process - this can affect how well other medicines, such as the contraceptive pill or HRT tablets, are absorbed by your body.
Guide to brand names:
| Medication | Brand name examples (commonly known as) |
| Tirzepatide | Mounjaro |
| Semaglutide | Wegovy, Ozempic, Rybelsus |
| Exenatide | Bydureon BCise |
| Liraglutide | Saxenda, Diavic, Victoza |
| Dulaglutide | Trulicity |
| Lixisenatide | Contained in Suliqua |
GLP-1 Agonists and Oral Contraception
What should I do if I am taking the contraceptive pill and using Tirzepatide or a semaglutide?
- Tirzepatide (Mounjaro): Tirzepatide may reduce how well the contraceptive pill works. You should use a non-oral methods of contraception (e.g. coil or implant) or a barrier method (like condoms) for four weeks after starting Mounjaro and also for four weeks after increasing your dose of Tirzepatide (Mounjaro). You should also use extra protection (like condoms) if you have vomiting or diarrhoea and should follow the missed pill rules (see the patient information leaflet which comes with your pill) if you vomit within 3 hours of taking the pill or have diarrhoea for more than 24 hours.
- Semaglutide (Ozempic, Wegovy, Rybelsus) and others: These do not appear to reduce the effectiveness of the pill currently however side effects like vomiting or diarrhoea can still reduce how well the pill is absorbed. Therefore you should use extra protection (like condoms) if you have vomiting or diarrhoea and follow the missed pill rules (see the patient information leaflet which comes with your pill) if you vomit within 3 hours of taking the pill or have diarrhoea for more than 24 hours.
- Other GLP-1 Medications such as Exenatide, Liraglutide, Dulaglutide and Lixisenatide are currently not known to have a direct interaction with oral contraception.
Is Emergency Contraception affected if I am taking a GLP-1 medication?
- We do not know yet if oral emergency contraception is affected by GLP-1 agonists. The copper IUD (Coil) is the most effective method of emergency contraception and is not affected by diarrhoea and vomiting. If you require emergency contraception, please ensure you tell the healthcare practitioner about all medication you are taking including GLP-1 agonists.
- Please see further information HERE which has been created by the Faculty of Sexual and Reproductive Healthcare (February 2025).
GLP-1 agonists and HRT medication
There is some concern that weight loss medications - such as Tirzepatide (Mounjaro) or Semaglutide (Wegovy) may reduce how well the progesterone tablets (Progesterone, Utrogestan, Norethisterone and Medroxyprogesterone Acetate) are absorbed. This could lead to irregular bleeding and may affect the protection of your womb lining (potentially leading to an increased risk of endometrial cancer).
What are my options if I am taking oral progesterone as part of my HRT medication and also on a GLP-1 agonist?
Options are changing the oral progesterone component of HRT to
- A Mirena Coil: which is the most ideal option as it works for 5 years as part of HRT and is also a contraception.
- Combined HRT Patch: contains both oestrogen and progesterone and bypasses the stomach
- Increasing the oral progesterone dose
Please request an appointment to discuss this with a GP if this affects you.