Can I take lactulose while pregnant or breastfeeding?
A plain-words look at what the NHS, the US drug label and LactMed say about lactulose.
In short
Pregnancy: Lactulose can be taken in pregnancy, but it's best to talk to a pharmacist or doctor first.
Breastfeeding: Lactulose can be taken while breastfeeding.
Your doctor, midwife or pharmacist can help you decide.
What this means for you
Breastfeeding
- Side effects in breastfed babies from medicines their mother takes are rare, but talk to a healthcare professional if anything about your baby worries you.
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
Lactulose in pregnancy
The NHS says
Lactulose can be taken in pregnancy, but it's best to talk to a pharmacist or doctor first.
In our words, from the NHS page Lactulose (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
Pregnancy Teratogenic Effects Pregnancy category B. Reproduction studies have been performed in mice, rats, and rabbits at doses up to 3 or 6 times the usual human oral dose and have revealed no evidence of impaired fertility or harm to the fetus due to lactulose. There are, however, no adequate and well-controlled studies in pregnant women. Because animal reproduction studies are not always predictive of human response, this drug should be used during pregnancy only if clearly needed.
Prescribing label, section “Pregnancy”: Lactulose (oral), American Health Packaging. Label on DailyMed. Quoted verbatim; US labels are written for US prescribers and patients.
More on lactulose in pregnancy: Bumps (Best Use of Medicines in Pregnancy) leaflet (external site).
Lactulose while breastfeeding
The NHS says
Lactulose can be taken while breastfeeding.
Side effects in breastfed babies from medicines their mother takes are rare, but talk to a healthcare professional if anything about your baby worries you.
In our words, from the NHS page Lactulose (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 clinical use of lactulose during breastfeeding. Because lactulose is poorly absorbed orally, it is unlikely to reach the breastmilk in large amounts. Any lactulose that the infant absorbs from milk is rapidly eliminated in the urine.[1] Some experts consider lactulose to be a laxative of choice during breastfeeding.[2] Lactulose is unlikely to adversely affect the breastfed infant and no special precautions are required.
“Summary of Use during Lactation”, LactMed record “Lactulose” (lactulose), quoted verbatim. Everything LactMed reports about Lactulose while breastfeeding.
The US prescribing label says
Nursing Mothers It is not known whether this drug is excreted in human milk. Because many drugs are excreted in human milk, caution should be exercised when lactulose solution is administered to a nursing woman.
Prescribing label, section “Nursing Mothers”: Lactulose (oral), American Health Packaging. Label on DailyMed. Quoted verbatim; US labels are written for US prescribers and patients.
Other names
Indian brands (per NPPA): Looz.
Sources
- NHS, Lactulose (nhs.uk), page last reviewed 8 September 2026. Paraphrased. Contains public sector information licensed under the Open Government Licence v3.0.
- US drug label: Lactulose (oral), American Health Packaging, human prescription drug, label effective 17 August 2026, set ID 8b79d0d6-b9e3-436e-bab7-01451b6f45cd. 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 “Lactulose” (lactulose), 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.
- Bumps (Best Use of Medicines in Pregnancy), UK Teratology Information Service: Bumps (Best Use of Medicines in Pregnancy) leaflet. Linked, not reproduced.
Sources checked 26 September 2026. How we source and check every page.
Educational summary of named sources, not medical advice.