Melatonin
Other supplementAlso called · 2 names▾▴
sleep hormone, melatonin supplement
Sleep supplement
Herbs and supplements are not FDA-approved before sale. About these sources
- Capsule/tablet
- Liquid extract
- Gummy
Research strength: 2 / 5
MotherToBaby says melatonin supplements have not been well studied in pregnancy. It also says a few human studies have not suggested more birth defects, while noting that it is not known whether melatonin can increase that chance. A 2022 scoping review found no trials that tested melatonin for sleep problems during pregnancy. The NHS says use is not usually recommended in pregnancy, and EMA product information for one prescription melatonin product says use is not recommended because human pregnancy data are lacking. The review's small trials for other conditions reported no major adverse outcomes, but the reviewed sources do not provide separate supplement findings for trimester 1. Ask your provider about your situation.
Last reviewed: 2026-10-14
Sources
- MotherToBaby: MelatoninTeratology service
- Vine et al., Melatonin use during pregnancy and lactation: a scoping review of human studiesUS government
- NHS: Pregnancy, breastfeeding and fertility while taking melatoninUK government
- EMA: Melatonin Neurim product informationEU agencyEuropean guidance
Research strength: 2 / 5
MotherToBaby says melatonin supplements have not been well studied in pregnancy. It says a few human studies have not suggested more birth defects, while also saying the chance is unknown. A 2022 review found no trials that tested melatonin for sleep problems during pregnancy. The NHS says use is not usually recommended in pregnancy, and EMA product information for one prescription product does not recommend use because clinical pregnancy data are lacking. The reviewed sources do not provide separate supplement findings for the second trimester. Ask your provider about your situation.
Last reviewed: 2026-10-14
Sources
- MotherToBaby: MelatoninTeratology service
- Vine et al., Melatonin use during pregnancy and lactation: a scoping review of human studiesUS government
- NHS: Pregnancy, breastfeeding and fertility while taking melatoninUK government
- EMA: Melatonin Neurim product informationEU agencyEuropean guidance
- Hobson et al., phase I trial in preeclampsiaUS government
- Miller et al., antenatal melatonin pilot study in fetal growth restrictionUS government
- Tang et al., assisted reproductive technology systematic review and meta-analysisUS government
Research strength: 2 / 5
MotherToBaby says melatonin supplements have not been well studied in pregnancy. It says a few human studies have not suggested more birth defects, while also saying the chance is unknown. A 2022 review found no trials that tested melatonin for sleep problems during pregnancy. The NHS and EMA product information say use in pregnancy is not recommended because clinical evidence is limited. One 2025 trial tested melatonin before cesarean delivery in women with placenta accreta, not for sleep, and found no significant difference in newborn respiratory distress; the reviewed sources do not provide separate supplement findings for trimester 3. Ask your provider about your situation.
Last reviewed: 2026-10-14
Sources
- MotherToBaby: MelatoninTeratology service
- Vine et al., Melatonin use during pregnancy and lactation: a scoping review of human studiesUS government
- NHS: Pregnancy, breastfeeding and fertility while taking melatoninUK government
- EMA: Melatonin Neurim product informationEU agencyEuropean guidance
- Ghotbizadeh Vahdani et al., antenatal melatonin randomized trial for neonatal respiratory distress syndromeUS government
Melatonin — Breastfeeding
Research strength: 2 / 5
LactMed says no data establish the effects of maternal melatonin supplements during breastfeeding, but it considers short-term use of usual evening doses unlikely to harm a breastfed infant. The 2022 review found no trials that tested melatonin as a sleep treatment during breastfeeding. MotherToBaby describes one infant bleeding report involving maternal melatonin and valerian, but the case does not establish the cause. The NHS says a healthy infant can be breastfed if a doctor or health visitor approves, while EMA product information says breastfeeding is not recommended during treatment; MotherToBaby says direct evidence is limited. Ask your provider about your situation.
Last reviewed: 2026-10-14
Sources
- LactMed: MelatoninUS government
- Vine et al., Melatonin use during pregnancy and lactation: a scoping review of human studiesUS government
- MotherToBaby: MelatoninTeratology service
- Iavarone et al., antiplatelet effect through breastfeeding: pediatric case reportUS government
- NHS: Pregnancy, breastfeeding and fertility while taking melatoninUK government
- EMA: Melatonin Neurim product informationEU agencyEuropean guidance
Pregnancy
MotherToBaby says it is not known whether melatonin supplements can increase the chance of birth defects; the few human studies it describes have not suggested an increase. A 2022 scoping review identified 8 pregnancy studies among 15 perinatal studies and found no randomized trials that tested melatonin for pregnancy-related sleep problems. The review describes small trials for other conditions, including preeclampsia and fetal growth restriction, that reported no major adverse events, but these findings do not establish effects for routine sleep use. Hobson et al. reported a phase I trial in 20 women with preeclampsia; treatment was associated with no reported adverse events and a 6 ± 2.3 day longer diagnosis-to-delivery interval than historical controls, but the trial was not randomized or a sleep study. A 2025 randomized trial in 60 women with placenta accreta spectrum found newborn respiratory distress in 5 of 30 melatonin-group infants versus 9 of 30 controls (p=0.228); among those with respiratory distress, 0 of 5 versus 6 of 9 needed intubation (p=0.016). The small trial was about treatment before cesarean delivery, not routine sleep use. A 2025 report in 404 women with gestational hypertension or preeclampsia used 30 mg melatonin daily until birth; its full text describes open-label, single-center recruitment, odd-even allocation by registration number, and more loss to follow-up in the melatonin group (26.8% versus 11.6%), which can bias the reported outcomes. A 2026 trial of melatonin with aspirin found no significant difference in preeclampsia or newborn outcomes; its abstract says 70 participants per group, while the results section reports 120 total, 60 per group. A 2025 meta-analysis of 11 assisted-reproduction trials found no significant difference in miscarriage rate (RR 0.96, 95% CI 0.50 to 1.82); this fertility-treatment finding does not answer effects of routine use during pregnancy. No reviewed source provides separate supplement findings for each trimester.
Breastfeeding
MotherToBaby says melatonin supplements during breastfeeding have not been well studied. LactMed says no data establish the effects of maternal supplementation, but it considers short-term use of usual evening doses unlikely to adversely affect an infant; it notes that some authors advise against use because of limited data and the longer half-life in preterm newborns. A 2022 scoping review found 7 breastfeeding studies, 3 involving exogenous melatonin, but no clinical trials testing maternal supplement use for sleep or infant outcomes. The 2023 case report described an 18-month-old with bleeding episodes and reduced platelet aggregation after breastfeeding; the mother used a mixture of melatonin and valerian. After maternal melatonin was stopped, platelet aggregation returned to normal and bleeding episodes did not recur. This single report cannot establish that melatonin caused the bleeding. NHS guidance says the amount of manufactured melatonin in milk is not known, is thought to be small, and longer use might make a baby sleepy. EMA product information for Melatonin Neurim says breastfeeding is not recommended during treatment. A 2025 ProMote cohort followed 122 breastmilk-fed preterm neonates and measured morning serum melatonin; results showed substantial variability without consistent differences by birth timing, postmenstrual age, or weight-for-gestational-age. An October 2026 cohort of 101 mothers and 128 preterm infants measured daytime milk melatonin and found it decreased from colostrum to mature milk across the first postnatal month. Neither cohort measured maternal supplement exposure, so neither resolves effects of supplements during lactation.
MotherToBaby describes melatonin as a hormone made by the body that helps regulate the sleep-wake cycle. NCCIH says the brain produces melatonin in response to darkness and that, in the United States, melatonin sold over the counter is considered a dietary supplement. Supplements may not contain the amount shown on the label.
What was tested
The 2022 scoping review included 15 human studies: 8 focused on pregnancy and 7 on breastfeeding. It found no randomized trials testing melatonin as a treatment for sleep disorders during pregnancy or breastfeeding. Pregnancy studies tested melatonin for other conditions, including preeclampsia and fetal growth restriction, or examined transfer across the placenta. Breastfeeding studies mainly measured normal day-night melatonin patterns in milk or infant levels; only one identified study concerned a breastfeeding mother's melatonin supplement use. Later trials tested melatonin as an add-on for specific high-risk pregnancy conditions, not routine treatment of sleep problems. Product-quality studies tested the amount of melatonin in sampled supplements and compared it with labels.
How to describe pregnancy evidence for melatonin supplements
- Source A says
- The 2022 scoping review reports that clinical trials using melatonin for other clinical conditions during pregnancy or breastfeeding had not suggested major adverse events. (Vine et al., Melatonin use during pregnancy and lactation: a scoping review of human studies, Hobson et al., Melatonin improves endothelial function in vitro and prolongs pregnancy in women with early-onset preeclampsia, Miller et al., Antenatal antioxidant treatment with melatonin to decrease newborn neurodevelopmental deficits and brain injury caused by fetal growth restriction)
- Source B says
- The NHS says melatonin is not usually recommended during pregnancy because little is known about its effect on babies. EMA product information says use in pregnant women is not recommended because clinical pregnancy data are lacking. (NHS: Pregnancy, breastfeeding and fertility while taking melatonin, EMA: Melatonin Neurim product information)
- Why they differ
- The review describes small trials for conditions such as preeclampsia and fetal growth restriction; it found no trials where sleep treatment was the main outcome. The NHS and EMA use a precautionary approach when pregnancy data are limited, and the EMA text is for a specific prescription product.
- Other sources
- MotherToBaby says it is not known whether melatonin can increase the chance of birth defects, while NCCIH notes a lack of research on melatonin use in pregnancy. (MotherToBaby: Melatonin, NCCIH: Melatonin: What You Need To Know)
- What the evidence shows overall
- The small condition-specific trials do not show a clear major harm signal, but they do not establish the effects of routine melatonin supplement use for sleep. Keep the rating at guidance and explain the evidence gap and differing recommendations.
Melatonin supplement use while breastfeeding
- Source A says
- LactMed considers short-term use of usual evening doses unlikely to adversely affect a breastfed infant. NHS guidance says a breastfeeding mother may use melatonin if a doctor or health visitor says the baby is healthy, while noting that longer use might cause sleepiness. (LactMed: Melatonin, NHS: Pregnancy, breastfeeding and fertility while taking melatonin)
- Source B says
- EMA product information says breastfeeding is not recommended during treatment with Melatonin Neurim. MotherToBaby says maternal supplement use has not been well studied and reports one infant bleeding case involving melatonin and valerian. (EMA: Melatonin Neurim product information, MotherToBaby: Melatonin, Iavarone et al., Antiplatelet Effect of Melatonin through Breastfeeding: A Pediatric Case Report)
- Why they differ
- The more permissive wording relies on an estimate of likely low exposure and is conditional on the infant's health. The EMA statement is a precaution in a product label, while direct studies of maternal supplement use and infant outcomes are scarce.
- Other sources
- The 2022 scoping review found no clinical trials testing maternal melatonin supplementation during breastfeeding, and the case report cannot establish cause. (Vine et al., Melatonin use during pregnancy and lactation: a scoping review of human studies, Iavarone et al., Antiplatelet Effect of Melatonin through Breastfeeding: A Pediatric Case Report)
- What the evidence shows overall
- The evidence does not settle this question. The single bleeding report involved valerian as well as melatonin and does not prove a cause. Keep the rating at guidance and show both the conditional NHS and LactMed view and the EMA restriction.
- MotherToBaby says many supplements are not recommended during pregnancy unless a healthcare provider has prescribed them to treat a medical condition. (MotherToBaby)
- The NHS says melatonin is not usually recommended during pregnancy because little is known about its effect on babies, and says a doctor can help decide whether to continue or stop if pregnancy occurs. (NHS)
- The NHS says a breastfeeding mother may use melatonin if a doctor or health visitor says the baby is healthy; it notes that the amount in milk is not known and longer use might make the baby sleepy. (NHS)
General research, not specific to pregnancy.
NCCIH describes melatonin as a hormone involved in sleep timing and notes that U.S. supplements are regulated differently from prescription or over-the-counter drugs. Two product-testing studies found discrepancies between labeled and measured amounts in sampled products; these results do not apply to every product.
- NCCIH says the brain produces melatonin in response to darkness and that it helps with the timing of circadian rhythms and sleep. (NCCIH: Melatonin: What You Need To Know)
- Erland and Saxena tested 31 commercial supplements. More than 71% did not meet the label claim within a 10% margin, and 8 of 31 contained serotonin. These were sampled products, not a test of every melatonin supplement. (Erland and Saxena, Melatonin Natural Health Products and Supplements: Presence of Serotonin and Significant Variability of Melatonin Content)
- Cohen and colleagues tested 25 melatonin gummies sold in the United States; 22 of 25 were inaccurately labeled, and measured melatonin ranged from 74% to 347% of the labeled amount. Only one sample of each brand was tested, so the study does not establish that every product or batch has the same content. (Cohen et al., Quantity of Melatonin and CBD in Melatonin Gummies Sold in the US)
- MotherToBaby: MelatoninTeratology serviceSecondary
- LactMed: MelatoninUS governmentSecondaryPage dated 2026-04-15Independent check
- NCCIH: Melatonin: What You Need To KnowUS governmentSecondaryIndependent check
- NHS: Pregnancy, breastfeeding and fertility while taking melatoninUK governmentSecondaryIndependent check
- EMA: Melatonin Neurim product informationEU agencySecondaryIndependent checkEuropean guidance
- Vine et al., Melatonin use during pregnancy and lactation: a scoping review of human studiesUS governmentPrimaryIndependent check
- Iavarone et al., Antiplatelet Effect of Melatonin through Breastfeeding: A Pediatric Case ReportUS governmentPrimaryIndependent check
- Hobson et al., Melatonin improves endothelial function in vitro and prolongs pregnancy in women with early-onset preeclampsiaUS governmentPrimaryIndependent check
- Miller et al., Antenatal antioxidant treatment with melatonin to decrease newborn neurodevelopmental deficits and brain injury caused by fetal growth restrictionUS governmentPrimaryIndependent check
- Ghotbizadeh Vahdani et al., Efficacy of Melatonin Administration in Pregnancy in Prevention of Neonatal Respiratory Distress Syndrome in Preterm NeonatesUS governmentPrimary
- Thora et al., Melatonin as an adjuvant therapy in gestational hypertension and pre-eclampsia: A randomized controlled trialUS governmentPrimary
- Alishahi et al., Effect of Adjuvant Melatonin in Preventing Preeclampsia in Women with Moderate to High-Risk FactorUS governmentPrimary
- Tang et al., Melatonin supplementation and outcomes of assisted reproductive technology: a systematic review and meta-analysisUS governmentPrimaryIndependent check
- Anagnostatou et al., Human Milk Melatonin Across Early Lactation in Preterm Birth: Maternal, Pregnancy, and Neonatal CorrelatesUS governmentPrimary
- Kokkinaki et al., Blood Melatonin in Breast Milk-Fed Preterm Infants: Longitudinal Biomonitoring to 38 Weeks' Postmenstrual AgeUS governmentPrimary
- Erland and Saxena, Melatonin Natural Health Products and Supplements: Presence of Serotonin and Significant Variability of Melatonin ContentUS governmentPrimaryIndependent check
- Cohen et al., Quantity of Melatonin and CBD in Melatonin Gummies Sold in the USUS governmentPrimaryIndependent check
- Alishahi et al., full-text resultsUS governmentPrimary
Last reviewed 2026-10-14
Independent check 2026-10-14
Not yet clinician-reviewed
Ask your provider about your situation.