Pregnancy and breastfeeding in the GLP-1 labels

Pregnancy, breastfeeding and planning: the documents side by side

The table lists what each document says in its own section. "Weigh benefits" means the label asks that the benefits of breastfeeding be considered together with the mother’s clinical need for the medicine and any possible effect on the infant; it neither recommends nor forbids. Zepbound® and Foundayo™ have no EU product information; in the EU, tirzepatide is sold as Mounjaro®.

Pregnancy, label by label

• Weight management (Wegovy®, Zepbound®, Saxenda®, Foundayo™): each label notes that losing weight brings no benefit in pregnancy and may harm the fetus, and that weight-reduction treatment is to be stopped once a pregnancy is known ^[1][4][6][7]. Wegovy® for the liver condition MASH is the exception: it may be used if the benefit justifies the risk, because MASH with advanced fibrosis carries its own risks for mother and baby ^[1].
• Type 2 diabetes (Ozempic®, Rybelsus®, Mounjaro®, Trulicity®): pregnancy use is reserved for cases where the possible benefit is judged to outweigh the possible risk. These labels stress that poorly controlled diabetes itself raises risks ^[2][3][5][8]; the Ozempic®, Mounjaro® and Trulicity® labels put the background rate of major birth defects at 6–10% when HbA1c around conception is above 7% ^[2][5][8].
• Europe: the semaglutide and liraglutide (Victoza®) documents say these medicines should not be used in pregnancy, and the Victoza® text adds that insulin is recommended instead; the Mounjaro® document says tirzepatide is not recommended in pregnancy or in women who could conceive and are not using contraception ^[9][10][11].
• Canada: the Zepbound® monograph lists pregnancy among its contraindications and notes that no clinical trials have been run in pregnancy; exposure in trials was limited to individual cases ^[12].
• Across the labels: human data are too limited to establish a drug-related risk of birth defects or miscarriage, and the possible fetal risk is inferred from animal studies. For context, the labels give the background rates in the general US population: major birth defects in 2–4% and miscarriage in 15–20% of clinically recognised pregnancies ^[1][4].

Before a planned pregnancy

Here the molecules and the countries differ most. The Ozempic®, Wegovy® and semaglutide tablet labels, and the EU Wegovy® document, set a gap of at least two months between the last dose of semaglutide and a planned pregnancy, citing its long washout; semaglutide’s half-life is about one week ^[1][2][3][9].

For tirzepatide, the US Mounjaro® and Zepbound® labels give no interval; tirzepatide’s half-life is about five days ^[4][5]. The EU Mounjaro® document and the Canadian Zepbound® monograph each give at least one month, again citing the half-life ^[10][12]. The US tirzepatide labels’ reproductive-potential section is instead about birth control pills, which tirzepatide may make less reliable in the first weeks and after dose increases. The Foundayo™ label asks women who could become pregnant to use effective contraception throughout treatment ^[6]. Which interval applies to you, and how to manage the condition being treated in the meantime, are questions for your prescriber.

Breast milk: what was measured

• Tirzepatide (Mounjaro®, Zepbound®): eleven healthy breastfeeding women received a single 5 mg dose and their milk was sampled for 28 days. Tirzepatide was undetectable in 164 of 171 samples; in the other seven, the combined amount was under 0.02% of the dose, and the last measurable level came five days after the injection. Effects on the baby and on milk supply are unknown ^[4][5].
• The EU Mounjaro® document adds that any small amount in milk is expected to be broken down rather than absorbed intact by the baby, that it is unknown whether the mother eating less changes the milk, and concludes that tirzepatide could be considered for use during breastfeeding ^[10].
• Semaglutide tablets (Wegovy® tablets, Rybelsus® and Ozempic® tablets): semaglutide itself was below the measurable limit in milk, but SNAC and its by-products were present, and infants may clear SNAC more slowly. Because injectable semaglutide contains no SNAC, the labels say breastfeeding is not recommended with the tablets ^[1][3].
• Semaglutide injections (Wegovy®, Ozempic®): no human milk data. The Ozempic® label reports that in rats, milk levels were 3 to 12 times lower than in the mother’s blood ^[2]. The EU Wegovy® document says semaglutide should not be used while breastfeeding ^[9].
• Liraglutide, dulaglutide and orforglipron: Saxenda® has no human data, and its Medication Guide asks you and your provider to decide between the medicine and breastfeeding ^[7]. Trulicity® has no human data ^[8]. Foundayo™ is not recommended for nursing women; in rats, milk levels were about three times blood levels ^[6].

Why weight loss matters in the animal findings

For semaglutide and tirzepatide, the harmful effects seen in animal fetuses coincided with reduced food intake and weight loss in the mothers ^[1][4]. Several labels explain their stance with the same point: appropriate weight gain, based on weight before pregnancy, is recommended for every pregnant person, including those with obesity or overweight, because some gain in the mother’s tissues is unavoidable ^[1][4].

Orforglipron is different. It does not act on the rat or rabbit receptor, so those studies could not show the class effect; in monkeys, doses below the highest human dose caused no fetal effects, and a rabbit range-finding study at 14 times human exposure found malformations, while the main rabbit study at up to six times found none ^[6]. The absorption enhancer SNAC in semaglutide tablets crossed the placenta in rats ^[1][3].

What studies of exposed pregnancies have found

Trials exclude pregnant women, so evidence comes from pregnancies in which a GLP-1 medicine was taken before the pregnancy was known. These are observational studies: they can show an association or its absence, but cannot prove that a medicine is safe.

• Nordic countries, the US and Israel, population cohort: among infants of women with type 2 diabetes, 938 were exposed to a GLP-1 medicine from 90 days before pregnancy to the end of the first trimester. Compared with insulin, the adjusted relative risk of major congenital malformations was 0.95, with a wide confidence interval; the authors call the result reassuring but needing confirmation ^[14].
• Six teratology information services, prospective cohort: 168 pregnancies exposed in the first trimester had major birth defects in 2.6%, against 2.3% in women with diabetes on other medicines and 3.9% in women with overweight or obesity, with no increase in pregnancy loss. The authors note that the small sample needs larger studies to confirm ^[15].

Registries and telling your care team

The Wegovy® and Zepbound® labels describe pregnancy exposure registries that follow women who used the medicine while pregnant, and encourage patients and providers to take part; the Foundayo™ label says such a registry is planned. Contact details are in each label’s section 8.1 ^[1][4][6].

The Wegovy® Medication Guide and the Zepbound® counselling section ask you to tell your healthcare provider if you are pregnant or plan a pregnancy during treatment, and the Wegovy® guide adds breastfeeding ^[1][4]. The Ozempic® Medication Guide asks you to talk with your provider about the best way to feed your baby ^[2].

Ozempic®, Wegovy®, Rybelsus®, Saxenda® and Victoza® are registered trademarks of Novo Nordisk A/S. Mounjaro®, Zepbound® and Trulicity® are registered trademarks and Foundayo™ is a trademark of Eli Lilly and Company. PepLabo is not affiliated with or endorsed by Novo Nordisk or Eli Lilly and Company.

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