GLP-1 medicines, pregnancy, contraception and fertility

Made with AI tools and overseen by an Australian GP · Updated 8 November 2026

The “Ozempic baby” headlines have a real message underneath: these medicines aren’t for pregnancy, and one of them can make the pill less reliable.

Quick answer: GLP-1 medicines aren’t used in pregnancy or breastfeeding. UK advice is to stop semaglutide at least 2 months, and tirzepatide at least 1 month, before trying to conceive. Tirzepatide (Mounjaro) may make the contraceptive pill less reliable, so add condoms or use a non-pill method for 4 weeks after starting and after each dose increase.

Pregnancy

• None of these medicines are recommended in pregnancy (TGA). There isn’t enough safety data to know whether they could harm a baby (MHRA).
• Use effective contraception while taking one if you could get pregnant.
• Stop before trying to conceive (UK MHRA): semaglutide (Ozempic, Wegovy) at least 2 months; tirzepatide (Mounjaro) at least 1 month; liraglutide just before trying.
• Pregnant while taking one? Talk to your doctor straight away.

Breastfeeding

• UK advice is not to take GLP-1 medicines while breastfeeding.

Tirzepatide and the pill

• The TGA updated Mounjaro’s product information in December 2025: reduced effectiveness of oral contraceptives “cannot be excluded”.
• If you use the pill, switch to a non-oral method or add a barrier method (such as condoms) for 4 weeks after starting and 4 weeks after each dose increase.
• Non-oral options include the implant, the IUD (coil) and condoms. See contraception.
• Semaglutide doesn’t carry this warning: in a US study it didn’t meaningfully change levels of the pill’s hormones.

Fertility

• In women with PCOS, a review of 11 trials linked GLP-1 medicines with more regular periods and higher natural pregnancy rates. See PCOS.
• The UK regulator has received more than 40 reports of pregnancies in people taking these medicines.
• So if you don’t want to get pregnant, reliable contraception matters. If you do, talk to your GP about timing and other ways to manage weight and blood sugar in the meantime.

See your GP as soon as you can if you become pregnant while taking a GLP-1 medicine. Get urgent help (000 in Australia, or your local emergency number) for heavy bleeding or severe tummy pain in early pregnancy.

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Evidence and more information

• TGA: Updated contraception advice for Mounjaro (tirzepatide)
• Australian Prescriber 2026: Updated contraception advice for Mounjaro (TGA Medicines Safety Update, December 2025)
• UK MHRA: GLP-1 medicines for weight loss and diabetes, what you need to know (updated February 2026)
• Pharmaceutical Journal, June 2025: MHRA urges effective contraception with weight-loss medicines
• STV News (PA), June 2025: More than 40 UK pregnancy reports
• Zhou et al, BMC Endocrine Disorders 2023: GLP-1 medicines, pregnancy rate and periods in PCOS, meta-analysis
• US FDA prescribing information for Wegovy (semaglutide), February 2026: side-effect table, warnings

Updated 8 November 2026. General education, not personal medical advice, and not a recommendation for any medicine. Whether a medicine suits you depends on your health and other medicines, so talk to your doctor or pharmacist.

maladywise.com/glp-1/pregnancy-contraception/