If you’re taking a medication like tirzepatide (Mounjaro) or semaglutide (Ozempic or Wegovy), for weight loss or type 2 diabetes, and you’re also using the combined oral contraceptive pill, it’s important to know that these might not always work well together. Weight loss injections belong to a group called GLP-1 receptor agonists (or dual agonists in the case of tirzepatide), which help lower blood sugar, reduce appetite, and support weight loss. One of the ways they do this is by slowing down how quickly food moves through your stomach—and that can also slow down how your body absorbs other medications, like the pill.
This can be a problem because the pill relies on being absorbed properly to be effective. If your stomach is emptying more slowly, or if you’re feeling nauseous, vomiting, or have diarrhoea (which are common side effects when starting weight loss injections), there’s a chance your body might not absorb enough of the hormones from the pill to prevent pregnancy. Because of this, the Faculty of Sexual and Reproductive Healthcare (FSRH) in the UK has issued guidance saying that there’s a potential risk of reduced effectiveness when taking oral contraception with GLP-1 medications like tirzepatide or semaglutide.
To stay on the safe side, the FSRH recommends using a non-oral form of contraception—such as the contraceptive implant, IUD (coil), injection, patch, or vaginal ring—since these options aren’t affected by the digestive system and are more reliable in this situation. If you prefer to stay on the pill, you might be advised to use extra protection like condoms, especially during the first few weeks of starting the weight loss medication or if you’re unwell.
If you’re currently on something like Mounjaro or Wegovy and using the pill, it’s a good idea to book an appointment to speak to one of our GPs or sexual health nurses. We can help you figure out what contraceptive method works best for you and make sure you’re fully protected. Everyone’s situation is different, so having that conversation can help you make the best choice for your health and peace of mind.
