GLP‑1s, Pregnancy and Breastfeeding: Ozempic, Wegovy, Zepbound and Mounjaro

The weight-loss labels say no: weight loss offers no benefit to a pregnant patient and may cause fetal harm.1,4 The Zepbound label tells patients to stop Zepbound when a pregnancy is recognized.1 The Wegovy label says to stop Wegovy in pregnant patients who use it for weight reduction or cardiovascular risk reduction.4

The diabetes labels are worded differently because poorly controlled diabetes in pregnancy carries its own risks.3,5 Ozempic and Mounjaro "should be used during pregnancy only if the potential benefit justifies the potential risk to the fetus."5

Why the caution? Human data are insufficient to judge the risk of birth defects or miscarriage.1,4 In animal studies, tirzepatide caused fetal growth reductions and abnormalities in rats at clinical exposures, and semaglutide caused embryo-fetal deaths, structural abnormalities and growth changes in rats at clinically relevant exposures.1,4 The labels note these effects coincided with reduced maternal weight and food intake.1,4

For context, the labels state that in the US general population, the background risk of major birth defects is 2% to 4% and of miscarriage 15% to 20% of clinically recognized pregnancies.1,4

Ozempic's label does not tell patients to stop on recognizing pregnancy, but says to use it only if the benefit justifies the potential risk, because data in pregnant women are limited.5 The label lists poorly controlled diabetes in pregnancy as a clinical consideration: the estimated background risk of major birth defects is 6% to 10% in women with pre-gestational diabetes.5 Decisions about diabetes treatment in pregnancy belong with the prescriber.

The Wegovy and Ozempic labels say to stop at least 2 months before a planned pregnancy, because semaglutide has a long half-life.4,5 Semaglutide's half-life is about 1 week, and the Wegovy label says it stays in the circulation for about 5 to 7 weeks after the last 2.4 mg or 7.2 mg injection or 25 mg tablet.4

The Zepbound and Mounjaro labels do not give a set washout period before a planned pregnancy.1,3 They say to stop Zepbound when pregnancy is recognized, and list the elimination half-life of tirzepatide as about 5 to 6 days in people with overweight or obesity.1 Ask your prescriber how far ahead to stop if you are planning a pregnancy.

Yes. GLP-1 labels do not describe these drugs as contraceptives, and the tirzepatide labels warn that they can make birth control pills less effective.1,3 That makes contraception planning part of starting treatment for anyone who could become pregnant.

Yes, for pills taken by mouth. Tirzepatide delays stomach emptying, which may reduce how well oral hormonal contraceptives work.1,3 The Zepbound and Mounjaro labels advise switching to a non-oral method, or adding a barrier method, for 4 weeks after starting and for 4 weeks after each dose increase.1,3 The labels say the delay is largest after the first dose and diminishes over time, and that hormonal contraceptives not taken by mouth should not be affected.1

On the Zepbound escalation schedule, the dose can rise every 4 weeks, so these 4-week windows can follow one another during the first months.1 Our Zepbound dosage guide lists each step.

The Wegovy and Ozempic labels do not carry this contraception warning.4,5 Our Wegovy vs Zepbound comparison sets out the other label differences between semaglutide and tirzepatide.

Tell your prescriber right away; for Wegovy and Zepbound the labels say to stop the drug when pregnancy is recognized.1,4 The Zepbound Medication Guide tells patients to inform their healthcare provider if they become pregnant while using it.2

Both manufacturers run pregnancy exposure registries that collect outcomes from people exposed during pregnancy:1,4

• Zepbound: call 1-844-524-0039 or visit pregnancyregistry.lilly.com/zepbound.1
• Wegovy: call Novo Nordisk at 1-877-390-2760 or visit wegovypregnancyregistry.com.4

The labels also note that weight gain appropriate to pre-pregnancy weight is currently recommended for all pregnant patients, including those with obesity or overweight.1

The Ozempic label says there are no data on semaglutide in human milk, but NIH's LactMed database says semaglutide was not detectable in the milk of mothers using the injection, and their breastfed infants had no adverse effects.5,7 LactMed says only injectable forms of semaglutide should be used during breastfeeding.7

The Ozempic label reports that semaglutide was present in the milk of lactating rats at levels 3 to 12 times lower than in maternal plasma, and says the clinical relevance is unclear.5 Like the other labels, it asks prescribers to weigh the benefits of breastfeeding against the mother's need for the drug and any potential effects on the infant.5

It depends on the form: the Wegovy label says breastfeeding is not recommended during treatment with Wegovy tablets, while the injection has no such recommendation.4 The tablets contain the absorption enhancer salcaprozate sodium (SNAC), which is present in human milk and may build up in infants.4 The label notes that other forms of semaglutide without SNAC can be used during lactation.4

For Wegovy injection, the label says there are no data on semaglutide in human milk and that the injection does not contain SNAC.4 LactMed's entry for semaglutide matches this: injectable forms only.7 Read more in our Wegovy pill guide.

The Zepbound and Mounjaro labels describe a lactation study in which tirzepatide was undetectable or low in breast milk.1,3 After a single 5 mg dose in 11 healthy lactating women, tirzepatide was undetectable in 164 of 171 milk samples.1 The total amount found over 28 days was less than 0.02% of the mother's dose.1

There are no data on effects on breastfed infants or on milk production.1 LactMed says that if a mother requires tirzepatide it is not a reason to stop breastfeeding, but that it should be used with caution, especially while nursing a newborn or preterm infant.6 The Zepbound Medication Guide tells patients who are breastfeeding to talk to their provider about the best way to feed their baby.2

Can you be on a GLP-1 while trying to get pregnant? The Wegovy and Ozempic labels say to stop at least 2 months before a planned pregnancy.4,5 Zepbound's label gives no set period and says to stop when pregnancy is recognized.1

Is it safe to take Ozempic while breastfeeding? LactMed reports semaglutide was not detectable in milk with the injection and infants had no adverse effects, but the label notes there are no human milk data.7,5

Do I need backup birth control on Wegovy? The Wegovy label has no oral-contraceptive warning; the backup advice applies to tirzepatide.4,1

How long does semaglutide stay in your body? About 5 to 7 weeks after the last dose, according to the Wegovy label.4 See how long GLP-1s stay in your system.

Does tirzepatide pass into breast milk? In the label's lactation study, tirzepatide was undetectable in most milk samples, and the total detected over 28 days was under 0.02% of the mother's dose.1

If you plan to start or restart a GLP-1 after pregnancy or breastfeeding, compare prescriber-led programs on our best GLP-1 programs page, and talk through timing with the prescriber you choose.

This article is for information only and is not medical advice. GLP-1 medications are prescription drugs with real risks and side effects. If you are pregnant, planning a pregnancy or breastfeeding, talk to a licensed clinician before starting, stopping or continuing any treatment.