Does Mounjaro Affect Birth Control?

Listen up, GLP-1 users! If you have been prescribed weight loss medication, it’s important you know that your usual hormonal birth control might not be reliable enough…

The latest game-changing weight management medications including Mounjaro (tirzepatide) or Wegovy (semaglutide) are proving invaluable to many of us who struggled to see results purely from CICO (calories in, calories out) regimes. However, alongside prepping meal plans and following guidance on how to safely take your tirzepatide, you also need to be clued up on the GLP-1 pregnancy risk. If it’s possible for you to get pregnant and you’re taking Mounjaro or Wegovy, The MHRA (The Medicines and Healthcare products Regulatory Agency) issued urgent contraception guidance for you.

Your Pill Might Not Be Working Properly (And Here's Why)

Whether you’re prescribed Mounjaro by an NHS GP or the private specialist weight management programme via HANX, GLP-1 medications work by mimicking hormones which make you feel full when eating. They slow down how quickly your stomach empties, which consequently can affect how well your body absorbs your contraceptive pill. With diarrhoea and vomiting both recognised side effects of GLP-1s, you may then be at risk of unplanned pregnancy - even though you thought you were protected.

The MHRA recommends if you use hormonal contraception (the contraceptive pill) to add a barrier method (like condoms) when having sex, or switch to a non-hormonal option altogether (a copper IUD, the implant or the patch). Using condoms is particularly important during two key windows: the first four weeks after starting Mounjaro, and then for four weeks after each dose increases.

Can you get pregnant on Mounjaro?

Since launching in the UK in 2023, the GLP-1 medication Mounjaro has proved pioneering development in how the medical profession supports patients with weight management. However, it is not intended for use:

• during pregnancy

• while trying to get pregnant

• during breastfeeding

So, what is the science behind the urgent advice to ensure you’re using effective contraception when taking GLP-1 medication? First things first: research shows that weight loss can naturally improve ovulation, which could boost chances of spontaneously conceiving. If you’re losing significant amounts of weight with the support of Mounjaro, which is simultaneously reducing effectiveness of your oral contraceptive pill, unintended pregnancy would well be a possibility.

The MHRA’s guidance was issued in response to around 40 reports from members of the public of suspected side-effects to GLP-1 medication, including 26 pregnancies. Whilst The MRHA states there "is not enough safety data to know whether taking a GLP-1 medicine can cause harm to a baby", there are good reasons to take all precautions to prevent pregnancy.

Aside from the potential impact of these medications on a baby, the side effects of GLP-1 medication can be even more tricky to navigate whilst pregnant. Morning sickness is a common symptom of pregnancy. When combined with the sometimes intense nausea caused by Mounjaro, this could not only be uncomfortable to experience but potentially cause dehydration and restrict nutrients reaching your baby.

How long should I wait to conceive after stopping taking GLP-1 medication?

With an estimated 500,000 people in the UK prescribed and taking GLP-1 medication via private weight management programmes, many have questions around future family planning. Planning for a baby post-treatment? The NHS has also issued clear advice on how long you need to stop these medications before trying to conceive:

• Semaglutide (Wegovy): 2+ months

• Tirzepatide (Mounjaro): 1+ month

• Liraglutide: Stop just before trying to conceive

What to do if you think you might be pregnant and you’re taking GLP-1 medication

As with all medication, it’s vital to follow medical guidance to ensure safe usage. Don't mess about if you're taking GLP-1 medications and you notice any of the below, make sure to get in touch with your healthcare provider:

• Your period's gone AWOL or you think you might be pregnant

• Unusual bleeding that could mean your hormonal birth control isn't working

• Really severe sickness that's stopping you eating or taking medication

The final word on Mounjaro birth control

If in doubt, have a chat about your chosen method with your GP or a healthcare professional before starting Mounjaro, Wegovy or any other GLP-1 medication. Not only can condoms, our favourite barrier method, reduce the chances of unintended pregnancy - they are the only prevention against sexually transmitted diseases. With a pack of johnnies in hand, go forth prepared and ready to make positive progress on your health journey with GLP-1 medications. 

Want more?

• Looking to start your weight management journey with GLP-1 medication? Start your consultation today to see if you’re eligible for the programme at HANX.

• Can you drink alcohol whilst taking weight management medication? Find out from our in-house medical experts.

• Why am I being shamed for taking Mounjaro? Find out why taboos around GLP-1 medication exist - and why they’re wrong.