Can I take lansoprazole while pregnant or breastfeeding?
A plain-words look at what the NHS, the US drug label and LactMed say about lansoprazole.
In short
Pregnancy: Lansoprazole can be taken in pregnancy, but you'll usually be offered a similar medicine, omeprazole, instead.
Breastfeeding: Let your doctor know if you're breastfeeding.
Your doctor, midwife or pharmacist can help you decide.
What this means for you
Pregnancy
- This is because much more is known about the safety of omeprazole in pregnancy.
- If your symptoms are mild, you may prefer to manage them without medicine.
- You can try eating little and often and cutting out spicy and fatty foods.
- Sitting up straight while you eat takes the pressure off your stomach.
- If you get symptoms at night, you could raise your head and shoulders when you go to bed.
- This helps stop stomach acid coming up while you're asleep.
Breastfeeding
- Lansoprazole can often be used while breastfeeding, but it's best to check first, as small amounts of the medicine can get into your breast milk.
- Your doctor will usually suggest omeprazole or pantoprazole instead.
- Side effects in breastfed babies from medicines their mother takes are rare.
- Even so, it's important to keep an eye on your baby while you take any medicine and breastfeed.
When to get help
- Contact a healthcare professional or call 111 (in the UK) as soon as you can if your baby is not feeding as well as they usually do; has difficulty pooing (constipation), has diarrhoea or is being sick (vomiting); is irritable or unsettled; or has difficulty sleeping.
- If your baby has any other symptoms, or you're worried about them, you can still call 111 or get in touch with any healthcare professional.
Talk to your doctor or pharmacist
This page is educational, not advice for your own situation. Talk to your doctor, midwife or pharmacist before you start, stop or change any medicine in pregnancy or while breastfeeding.
The details: what each source says
Lansoprazole in pregnancy
The NHS says
Lansoprazole can be taken in pregnancy, but you'll usually be offered a similar medicine, omeprazole, instead. This is because much more is known about the safety of omeprazole in pregnancy.
If your symptoms are mild, you may prefer to manage them without medicine. You can try eating little and often and cutting out spicy and fatty foods. Sitting up straight while you eat takes the pressure off your stomach.
If you get symptoms at night, you could raise your head and shoulders when you go to bed. This helps stop stomach acid coming up while you're asleep.
In our words, from the NHS page Lansoprazole (nhs.uk). Contains public sector information licensed under the Open Government Licence v3.0 (OGL v3.0). The NHS does not endorse this site.
The US drug label says
If pregnant or breast-feeding, ask a health care professional before use.
Drug Facts label: LANSOPRAZOLE (oral), Amazon.com Services LLC. Label on DailyMed. Quoted verbatim; US labels are written for US prescribers and patients.
8.1 Pregnancy Risk Summary Available data from published observational studies overall do not indicate an association of adverse pregnancy outcomes with lansoprazole treatment (see Data) . In animal reproduction studies, oral administration of lansoprazole to rats during organogenesis through lactation at 6.4 times the maximum recommended human dose produced reductions in the offspring in femur weight, femur length, crown-rump length and growth plate thickness (males only) on postnatal Day 21 (see Data) . These effects were associated with reduction in body weight gain. Advise pregnant women of the potential risk to the fetus. The estimated background risk of major birth defects and miscarriage for the indicated populations are unknown. All pregnancies have a background risk of birth defect, loss, or other adverse outcomes. In the US general population, the estimated background risk of major birth defects and miscarriage in clinically recognized pregnancies is 2 to 4% and 15 to 20%, respectively. If lansoprazole delayed-release orally disintegrating tablets are administered with clarithromycin, the pregnancy information for clarithromycin also applies to the combination regimen.
Prescribing label, section “8.1 Pregnancy” (opening excerpt): Lansoprazole (oral), Cardinal Health 107, LLC. Read the full section on DailyMed. Quoted verbatim; US labels are written for US prescribers and patients.
Lansoprazole while breastfeeding
The NHS says
Let your doctor know if you're breastfeeding.
Lansoprazole can often be used while breastfeeding, but it's best to check first, as small amounts of the medicine can get into your breast milk. Your doctor will usually suggest omeprazole or pantoprazole instead.
Side effects in breastfed babies from medicines their mother takes are rare. Even so, it's important to keep an eye on your baby while you take any medicine and breastfeed.
Contact a healthcare professional or call 111 (in the UK) as soon as you can if your baby is not feeding as well as they usually do; has difficulty pooing (constipation), has diarrhoea or is being sick (vomiting); is irritable or unsettled; or has difficulty sleeping.
If your baby has any other symptoms, or you're worried about them, you can still call 111 or get in touch with any healthcare professional.
In our words, from the NHS page Lansoprazole (nhs.uk). Contains public sector information licensed under the Open Government Licence v3.0 (OGL v3.0). The NHS does not endorse this site.
LactMed says
No information is available on the use of lansoprazole during breastfeeding. However, lansoprazole has been used safely in newborn infants, so it is unlikely that the amount in breastmilk would be harmful.
“Summary of Use during Lactation”, LactMed record “Lansoprazole” (LM411), quoted verbatim. Everything LactMed reports about Lansoprazole while breastfeeding.
What these words mean
- metabolite
- a substance made when the body breaks down a medicine
Definitions adapted from the NCI Dictionary of Cancer Terms (National Cancer Institute).
The US prescribing label says
8.2 Lactation Risk Summary There is no information regarding the presence of lansoprazole in human milk, the effects on the breastfed infant, or the effects on milk production. However, lansoprazole and its metabolites are present in rat milk. The developmental and health benefits of breastfeeding should be considered along with the mother’s clinical need for lansoprazole delayed-release orally disintegrating tablets and any potential adverse effects on the breastfed child from lansoprazole delayed-release orally disintegrating tablets or from the underlying maternal condition.
Prescribing label, section “8.2 Lactation”: Lansoprazole (oral), Cardinal Health 107, LLC. Label on DailyMed. Quoted verbatim; US labels are written for US prescribers and patients.
Other names
UK brand names (per the NHS): Zoton FasTabs.
Sources
- NHS, Lansoprazole (nhs.uk), page last reviewed 3 December 2025. Paraphrased. Contains public sector information licensed under the Open Government Licence v3.0.
- US drug label: LANSOPRAZOLE (oral), Amazon.com Services LLC, human otc drug, label effective 12 August 2026, set ID d0a7e6e0-9a76-4a5a-aed7-aa976a174c0e. DailyMed (National Library of Medicine). Public domain; quoted verbatim.
- US drug label: Lansoprazole (oral), Cardinal Health 107, LLC, human prescription drug, label effective 20 May 2026, set ID c9a43df0-efab-4486-860f-92afdb258c8b. DailyMed (National Library of Medicine). Public domain; quoted verbatim.
- Drugs and Lactation Database (LactMed), National Institute of Child Health and Human Development (NICHD), via NCBI Bookshelf, record “Lansoprazole” (LM411), bulk release of 22 September 2026. LactMed on NCBI Bookshelf. Public domain; quoted verbatim. LactMed is a registered trademark of the U.S. Department of Health and Human Services.
Sources checked 26 September 2026. How we source and check every page.
Educational summary of named sources, not medical advice.