If you're taking or considering a GLP-1 medication and are of childbearing age, pregnancy planning is an important conversation to have with your prescriber. Here's the key guidance.
Not recommended during pregnancy
All GLP-1 weight loss medications are not recommended during pregnancy or breastfeeding. There is limited safety data from human pregnancies, and animal studies have shown potential risks including reduced fetal growth and developmental effects. Based on this, the MHRA advises against use in pregnancy.12
This applies to Mounjaro (tirzepatide), Wegovy (semaglutide), Saxenda (liraglutide), and Ozempic (semaglutide).
When to stop before trying to conceive
Because these medications have long half-lives (they stay in your system for days after the last injection), you need to stop well before attempting pregnancy:12
- Mounjaro (tirzepatide): Stop at least 1 month (4 weeks) before planning pregnancy
- Wegovy/Ozempic (semaglutide): Stop at least 2 months (8 weeks) before planning pregnancy
- Saxenda (liraglutide): Stop at least 2 months before planning pregnancy
These timeframes allow the medication to fully clear from your system before conception.
If you become pregnant during treatment
If you discover you're pregnant while taking a GLP-1 medication, stop taking it immediately and contact your GP or prescriber. Don't wait for your next scheduled appointment — call as soon as you know.
Becoming pregnant during treatment doesn't necessarily mean there will be a problem, but your healthcare team needs to know so they can monitor the pregnancy appropriately and provide relevant guidance.
The contraception factor
This is particularly important for Mounjaro users. Tirzepatide may reduce the effectiveness of oral contraceptive pills (see our detailed guide). If you're relying on the pill for contraception while taking Mounjaro, you may be at increased risk of unintended pregnancy — making the stopping timeline above even more critical to be aware of.
If pregnancy prevention is important to you, consider using a non-oral method of contraception (implant, IUD, injection, patch) that isn't affected by Mounjaro's gastric emptying effects.
Breastfeeding
GLP-1 medications are not recommended during breastfeeding. It is not known whether tirzepatide or semaglutide pass into human breast milk, and given the potential for adverse effects on a nursing infant, the manufacturers and MHRA advise against use while breastfeeding.12
Weight management during pregnancy
If you stop GLP-1 medication to become pregnant, you may be concerned about weight regain. Speak to your GP or midwife about safe weight management during pregnancy. NICE guidelines recommend that women with obesity who become pregnant should receive tailored dietary and physical activity advice. Healthy eating and moderate exercise during pregnancy are safe and beneficial for most women.