Weight Loss Medication and Pregnancy

Weight loss medication safety during pregnancy and breastfeeding in Australia.

The clear rule

Weight loss medications should NOT be used during pregnancy or while breastfeeding. This applies to all TGA-approved options — Wegovy, Mounjaro, Ozempic, Duromine, Contrave, and Xenical.

Before getting pregnant

If you're planning to become pregnant, you should stop weight loss medication at least 2 months before trying to conceive. For GLP-1 medications (Wegovy, Mounjaro), the recommendation is to stop at least 2 months before planned conception to allow the medication to clear your system.

What if I become pregnant while on medication?

Stop the medication immediately and contact your doctor. While there is limited data on pregnancy outcomes with GLP-1 medications, animal studies have shown potential risks. Your doctor will advise on next steps.

After pregnancy

Weight loss medication may be an option after you finish breastfeeding. Many women experience difficulty losing pregnancy weight, and medication can be a useful tool alongside diet and exercise once it's medically appropriate. Discuss timing with your doctor.

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Planning pregnancy: the timeline

The recommended washout periods before attempting conception:

Medication	Stop how long before?	Why
Wegovy (semaglutide)	At least 2 months	Long half-life; needs time to clear
Mounjaro (tirzepatide)	At least 2 months	Same reason; limited pregnancy data
Duromine (phentermine)	Immediately	Short half-life; clears quickly
Contrave	At least 2 weeks	Bupropion crosses placenta
Xenical (orlistat)	Can continue to conception	Minimal systemic absorption; stop when pregnant

Weight loss before pregnancy can improve outcomes

Losing weight before pregnancy — even 5–10% — significantly reduces the risk of gestational diabetes, pre-eclampsia, and pregnancy complications. If you're planning pregnancy in the next 6–12 months, weight loss medication can be a valuable tool to optimise your health before conception.

Post-pregnancy weight loss

After completing breastfeeding, weight loss medication can help with post-pregnancy weight retention. Many women find that pregnancy weight is particularly resistant to diet and exercise alone, especially with the hormonal and lifestyle changes of new parenthood. Discuss timing with your GP or obstetrician.