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Is melatonin safe during pregnancy?

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

NCCIH says research on melatonin in pregnant or breastfeeding women is lacking. A Cochrane review found no randomized trials of melatonin given to pregnant women for protecting the fetal brain, and a 2022 review of 8 pregnancy studies found none testing it for sleep problems. Ask your doctor before taking it.1,2,3

Key facts

  • NCCIH says there has been a lack of research on the safety of melatonin use in pregnant or breastfeeding women.1
  • A Cochrane review searching to January 2016 found no randomized trials of melatonin given to pregnant women for protecting the fetal brain.2
  • A 2022 scoping review of 15 human studies, 8 of them in pregnancy, found no randomized trials of melatonin for sleep problems in pregnant or breastfeeding women.3
  • The authors of that review said clinical trials for other purposes had not suggested major safety concerns, and called for more studies in sleep problems during pregnancy and lactation.3
  • No source we read breaks its findings down by trimester.1,3

What does NCCIH say about melatonin in pregnancy?

NCCIH's page on melatonin does not rule it out or approve it. It says there has been a lack of research on the safety of melatonin use in pregnant or breastfeeding women, and that anyone who is pregnant or nursing a child should see a health care provider before taking any medicine or supplement, melatonin included.1

No upper limit has been set for melatonin. NCCIH says there is not yet enough information on side effects, especially at doses higher than the body makes, for a clear picture of its overall safety, and information on long-term use is lacking.1

What have reviews of the human evidence found?

Two reviews looked for trials. The first is a Cochrane review that searched for randomized trials of melatonin given to pregnant women to protect the fetal brain. It found none through January 2016, and one trial under way, so the reviewers could not comment on what practice should be.2

The second is a 2022 scoping review of 15 human studies of melatonin in pregnancy and breastfeeding, 8 of them in pregnancy, which included case reports, cohort studies and clinical trials. It found no randomized trials testing melatonin as a treatment for sleep problems in either group. Clinical trials that gave melatonin for other reasons did not suggest major safety concerns or adverse events.3

The authors went further than NCCIH. Their conclusion was that, contrary to what animal studies had suggested, the clinical evidence so far points to melatonin use in pregnancy and breastfeeding being probably safe for humans. Weigh that against the kind of evidence it rests on: a mix of small studies, none designed to test sleep outcomes in pregnancy, which the authors themselves said are needed.3

What is still not known?

The sources leave several questions open. They do not say which amount, if any, has been studied for sleep in pregnancy. They do not separate early from late pregnancy. And they do not tell a pregnant person whether the doses used in other trials, often for other medical reasons, match what a store-bought supplement provides.1,3

That last point matters because supplement contents vary. NCCIH reports two studies that tested products on the market, and found amounts that often did not match the label.1

In a 2017 study of 31 melatonin supplements, the amount in most products did not match the label, and 26 percent of them contained serotonin.1,4

In a 2023 study, 22 of 25 melatonin gummy products were inaccurately labeled. One had no detectable melatonin, and the rest held 74 to 347 percent of the amount on the label.1,5

Who should ask a doctor about melatonin in pregnancy?

Ask your doctor, midwife or obstetric provider before taking melatonin if you are pregnant or trying to become pregnant. Sleep that is badly disrupted in pregnancy is itself worth raising with them, since the cause may be something they can address.

  • Bring the label, including the amount per tablet or gummy and any other ingredients, because supplement labels can be inaccurate.1
  • Mention any medicine you take, since NCCIH advises medical supervision for people on blood thinners or with epilepsy.1
  • Ask how long you can expect any plan to continue, since the sources do not describe long-term use in pregnancy.

Questions people ask

Is melatonin safe during pregnancy in the third trimester?

None of the sources break their findings down by trimester, so none answers for the third trimester specifically. NCCIH says research is lacking and advises seeing a provider first. Ask your doctor.1,3

Is melatonin safe in the first trimester?

The same gap applies to early pregnancy: no source separates it from later pregnancy. Ask your doctor or midwife before taking melatonin.1

Is melatonin safe during pregnancy according to ACOG?

Guidance from the American College of Obstetricians and Gynecologists is not among the sources on this page. NCCIH says research is lacking and that anyone pregnant should see a health care provider first.1

Is melatonin bad during pregnancy?

No source we read reports that melatonin harmed a pregnancy, and the sources also say the studies needed are lacking. Ask your doctor.1,2,3

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Sources

  1. National Center for Complementary and Integrative Health. Melatonin: What You Need To Know. Bethesda (MD): National Institutes of Health. Last updated May 2024. Opened 2026-10-07.
  2. Wilkinson D, Shepherd E, Wallace EM. Melatonin for women in pregnancy for neuroprotection of the fetus. Cochrane Database Syst Rev. 2016;3:CD010527. Opened 2026-10-11.
  3. Vine T, Brown GM, Frey BN. Melatonin use during pregnancy and lactation: a scoping review of human studies. Braz J Psychiatry. 2022;44(3):342-348. Opened 2026-10-11.
  4. Erland LAE, Saxena PK. Melatonin natural health products and supplements: presence of serotonin and significant variability of melatonin content. J Clin Sleep Med. 2017;13(2):275-281. Opened 2026-10-01.
  5. Cohen PA, Avula B, Wang YH, Katragunta K, Khan I. Quantity of melatonin and CBD in melatonin gummies sold in the US. JAMA. 2023;329(16):1401-1402. PMCID: PMC10130950. Opened 2026-10-01.

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