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Is L-glutamine safe while breastfeeding?

Written by the Full Measure editorial team, which sells supplements. Approved for publication by the Full Measure owners. Updated .

Drafted with AI assistance from the sources listed below. How we write these

Quick answer

The FDA label for prescription L-glutamine says there are no data on glutamine in human milk, on its effect on a breastfed infant, or on lactation. Searches of NIH's breastfeeding drug database, LactMed, found no entry for glutamine. NIH advises caution with supplements while nursing. Ask your doctor before taking glutamine while breastfeeding.1,2

Key facts

  • The label says there are no data on L-glutamine in human milk, on its effect on the breastfed infant, or on its effect on lactation.1
  • Searches of LactMed in October 2026 found no entry for glutamine.3
  • The main trial behind the label excluded lactating women, so it cannot answer the question.1
  • MedlinePlus asks users of the prescription form to tell their doctor if they are breastfeeding.4

What the label says about breastfeeding

The lactation section of the prescription label is brief. It says there are no data on the presence of L-glutamine in human milk, on the effect on the breastfed infant or on the effect on lactation. It then says the developmental and health benefits of breastfeeding should be weighed together with the mother's clinical need for the medicine and any potential adverse effects on the breastfed child, from the medicine or from the mother's condition.1

That wording reports a gap in knowledge, not a finding about infants. The same label says its main trial excluded women who were lactating.1

What LactMed has on glutamine

LactMed is the National Library of Medicine's database of drugs and substances that nursing mothers may be exposed to. Searches of its records in October 2026, on NCBI Bookshelf and through PubChem's copy, found entries for creatine, vitamin D, vitamin K and several magnesium salts, but none for glutamine. The sources checked therefore include no LactMed summary of glutamine for nursing mothers.3

How this fits with what NIH reports

Glutamine is made by the body, and NIH says adults eat about 3 to 6 g a day from protein foods. NIH's exercise fact sheet describes trials of glutamine supplements in healthy adults at up to about 45 g a day with no side effects reported, and says daily doses of 0.21 to 0.42 g per kg of body weight showed no evidence of toxicity in patients with serious illnesses. None of those studies was in nursing mothers.5,6

NIH's general advice is to be cautious with supplements beyond a standard prenatal supplement while nursing, because many have not been well tested in nursing women. A 2022 review of amino acid supplements also lists nursing a baby among the circumstances that need more research.2,7

Who should ask their doctor

Ask your doctor, midwife or a lactation consultant before taking glutamine, or a blend that contains it, while breastfeeding. MedlinePlus asks anyone using the prescription form to tell their doctor if they are breastfeeding. People with liver disease, a urea cycle disorder or kidney disease should also ask first, because a safety review notes glutamine is broken down to ammonia.4,7

Questions people ask

Is L-glutamine safe during breastfeeding?

The prescription label says there are no data on glutamine in human milk or on its effect on a breastfed infant. That is a gap in knowledge, not a finding of harm. Ask your doctor.1

Can you take amino acids while breastfeeding?

The sources checked are about glutamine only, and they do not cover amino acid supplements as a group. A 2022 review lists nursing among the situations that need more research, so ask your doctor about each product.7

Does breast milk contain glutamine?

The sources checked do not say, and the label states there are no data on the presence of L-glutamine in human milk. That is not a finding either way.1

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Sources

  1. L-glutamine oral powder: prescribing information (Camber Pharmaceuticals). DailyMed, U.S. National Library of Medicine. Published June 11, 2026. Opened 2026-10-07.
  2. National Institutes of Health, Office of Dietary Supplements. Dietary Supplements: What You Need To Know. Fact sheet for consumers. Updated January 4, 2023. Opened 2026-10-07.
  3. Drugs and Lactation Database (LactMed). Bethesda (MD): National Institute of Child Health and Human Development; 2006-. Searches run October 2026 on NCBI Bookshelf and through PubChem's copy of the LactMed records, because the Bookshelf pages block scripts. Opened 2026-10-11.
  4. MedlinePlus, U.S. National Library of Medicine. L-glutamine (drug information). Last revised September 15, 2017. Opened 2026-10-01.
  5. National Institutes of Health, Office of Dietary Supplements. Dietary Supplements for Exercise and Athletic Performance: Fact Sheet for Health Professionals. Updated April 1, 2024. Opened 2026-10-07.
  6. National Institutes of Health, Office of Dietary Supplements. Dietary Supplements for Exercise and Athletic Performance: Fact Sheet for Consumers. Updated March 22, 2021. Opened 2026-10-07.
  7. Holeček M. Side effects of amino acid supplements. Physiol Res. 2022;71(1):29-45. Opened 2026-10-01.

This page is information, not medical advice. Talk to your doctor or pharmacist about your own situation.