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Melatonin research

What published studies found for Melatonin: 8 papers, 8 in humans, with sample sizes and key results, plus 283 registered clinical trials.

A
Strong human evidence
Why: Multiple meta-analyses of RCTs (thousands of people) show modest, consistent gains in sleep onset and jet lag; benefit in adult chronic insomnia is small or absent.

Melatonin has a large body of RCTs and meta-analyses showing modest improvements in sleep onset latency, total sleep time and jet lag; benefits are small, and some analyses (adult chronic insomnia, dementia, network meta-analysis vs hypnotics) find no material benefit.

✓ 4 positive✗ 2 negative~ 2 mixed

Serious adverse events were not increased in pooled trials, but adverse-event reporting in melatonin trials is often incomplete.

US compounding: Compounding allowed (Category 1). In 503A Category 1: pharmacies may compound it while FDA evaluates it. Status for every peptide.

Browse and filter these papersMelatonin prices and vendors

Reported side effects

Registered clinical trials

283 trials of Melatonin on ClinicalTrials.gov: 54 active, 132 completed, 32 with posted results. Registered trials include ones that haven't published yet.

TrialStatusPhasePeopleSponsor
Melatonin and Risk Of Cardiovascular Events And Malignant Tumors In The ElderlyNCT04631341 · started 2021-01-01Not yet recruiting–10,000RenJi Hospital
Effect of Preoperative Sleep Intervention on Postoperative Delirium in Adult Patients Undergoing Cardiac SurgeryNCT06777342 · started 2025-02-01Not yet recruiting–1,281Yan Fuxia
A SMART Approach to Evaluating the Benefits of Common Prescription and OTC Medications for InsomniaNCT07542756 · started 2026-05-01RecruitingPhase 41,200University of Pennsylvania
Melatonin for Prevention of Kidney InjuryNCT05084196 · started 2023-06-05RecruitingPhase 3300Rutgers, The State University of New Jersey
Melatonin for Patients With Chronic Low Back PainNCT06859957 · started 2025-04-11Active, not recruitingPhase 3222Bart Koes
Melatonin vs Midazolam in Children Undergoing TonsillectomyNCT07336095 · started 2026-03-01Not yet recruitingPhase 3195Ain Shams University
The Basel BOMP-AID Randomized TrialNCT03438526 · started 2022-01-03RecruitingPhase 4190University Hospital, Basel, Switzerland
Melatonin and Solifenacin for Double-J Ureteral Stent SymptomsNCT07617922 · started 2026-05-07RecruitingPhase 2189Beni-Suef University
Efficacy of Chronotherapeutic Combination for Major Depressive Episode With InsomniaNCT07120880 · started 2026-01-28RecruitingPhase 3184Assistance Publique - Hôpitaux de Paris
Efficacy of CBT-I With Adjuvant Melatonin in Older Adults Chronic InsomniaNCT07695246 · started 2026-08-01Recruiting–183The University of Hong Kong
Combination Therapy for Treatment of Sleep Disturbance in Patients With Advanced CancerNCT05474846 · started 2022-11-21Active, not recruitingPhase 2, Phase 3169M.D. Anderson Cancer Center
Effects of Melatonin on Excessive Crying in Neonates. A Randomized Controlled Clinical Trial.NCT07442162 · started 2026-02-23Enrolling by invitationPhase 1, Phase 2165Al-Hadba university

All 283 Melatonin trials, with countries and recruiting status

Meta-analyses & systematic reviews

✓ Positivemeta-analysisJ Sleep Res · 2023

Efficacy of melatonin and ramelteon for the acute and long-term management of insomnia disorder in adults: A systematic review and meta-analysis.

n = 4,875 humansSystematic review and meta-analysis (PRISMA)

22 studies in insomnia disorder: prolonged-release melatonin gave small-to-medium improvements in sleep onset latency (~5–6 min) and sleep efficiency vs placebo.

Key resultProlonged-release melatonin vs placebo: subjective sleep onset latency weighted difference = -6.30 min (p = 0.031); objective sleep onset latency -5.05 min (p < 0.001)
Studied
Adults with insomnia disorder
Compared with
Placebo
Main outcome
Sleep onset latency, sleep efficiency, total sleep time
Sample
22 studies, 4875 participants (925 melatonin, 1804 ramelteon, 2297 placebo)
Authors' conclusion
Prolonged-release melatonin and ramelteon appear efficacious versus placebo for insomnia symptoms; melatonin effects are mostly small to medium, larger for mean age 55 or older and for ramelteon.
Limitations
Low level of evidence noted; most studies evaluated acute efficacy of prolonged-release melatonin.
PubMed 37434463DOI
~ Mixedmeta-analysisJ Pineal Res · 2022

Safety of higher doses of melatonin in adults: A systematic review and meta-analysis.

n = 3,861 humansSystematic review and meta-analysis of RCTs

Safety review of high-dose (≥10 mg) melatonin RCTs: no detectable increase in serious adverse events, but more adverse events such as drowsiness, headache and dizziness (rate ratio 1.40).

Key resultIn 4 low-risk-of-bias studies, no detectable increase in serious AEs (Rate Ratio = 0.88 [0.52, 1.50], p = .64) but increased AEs such as drowsiness, headache and dizziness (1.40 [1.15, 1.69], p < .001)
Studied
Adults over 30 years given high-dose melatonin (10 mg or more) across medical conditions
Main outcome
Adverse events, serious adverse events, withdrawals due to adverse events
Sample
79 studies, 3861 participants
Authors' conclusion
Based on limited evidence, melatonin appears to have a good safety profile; better safety reporting in long-term trials is needed.
Limitations
29 studies (37%) did not report AEs; only four met low risk of bias; confidence limits very wide.
PubMed 34923676DOI
✓ Positivemeta-analysisPLoS One · 2013

Meta-analysis: melatonin for the treatment of primary sleep disorders.

n = 1,683 humansMeta-analysis of randomized placebo-controlled trials

19 RCTs (1,683 people) with primary sleep disorders: melatonin shortened sleep latency by ~7 min, increased total sleep by ~8 min and improved sleep quality; effects modest.

Key resultSleep latency reduced by WMD = 7.06 minutes (95% CI 4.37 to 9.75, p<0.001); total sleep time increased by 8.25 minutes (95% CI 1.74 to 14.75, p = 0.013)
Studied
Adults and children with primary sleep disorders
Compared with
Placebo
Main outcome
Sleep latency, sleep quality, total sleep time
Sample
19 studies, 1683 subjects
Authors' conclusion
Melatonin decreases sleep onset latency, increases total sleep time and improves sleep quality; effects are modest but do not appear to dissipate with continued use, and are smaller than other pharmacological insomnia treatments.
Limitations
Effects are modest in absolute terms.
PubMed 23691095DOIFree full text
Figure 1: Efficacy of Melatonin in Reducing Sleep Latency.Forest plot depicting reduction of sleep latency in melatonin compared to placebo. Meta-anal
Figure 1. From PMC3656905, CC BY (terms); resized.
✓ Positivemeta-analysisJ Pineal Res · 2024

Optimizing the Time and Dose of Melatonin as a Sleep-Promoting Drug: A Systematic Review of Randomized Controlled Trials and Dose-Response Meta-Analysis.

26 RCTs, 1689 observationsSystematic review and dose-response meta-analysis of double-blind RCTs

Dose-response meta-analysis of 26 RCTs: melatonin reduced sleep onset latency and increased total sleep time, with effect peaking around 4 mg/day and when taken earlier before bed.

Key resultMelatonin effect on sleep onset latency and total sleep time peaked at 4 mg/day in dose-response analysis; insomnia status was a significant predictor of sleep onset latency (beta = 0.50, p < 0.001)
Studied
Patients with insomnia and healthy volunteers
Compared with
Placebo
Main outcome
Sleep onset latency and total sleep time (standardized mean difference)
Authors' conclusion
Earlier administration (3 h before desired bedtime) and a 4 mg/day dose, compared with the commonly used 2 mg 30 min before bedtime, might optimize melatonin's sleep-promoting efficacy.
Limitations
Suggestion derived from meta-regression and dose-response modelling of heterogeneous trials.
PubMed 38888087DOI
✓ Positivemeta-analysisMedwave · 2015

Is melatonin useful for jet lag?

4 systematic reviews including 11 randomized trialsMeta-analysis of randomized trials identified via Epistemonikos, GRADE summary of findings

Pooled 11 randomized trials: oral melatonin probably reduces jet lag symptoms; adverse effects unclear but probably mild.

Studied
Travelers with jet lag syndrome
Main outcome
Jet lag symptoms
Authors' conclusion
Oral melatonin probably reduces symptoms associated with jet lag syndrome; unclear whether it produces adverse effects, but they would probably be mild.
Limitations
Abstract gives no numerical results.
PubMed 26731279DOI
✗ Negativemeta-analysisLancet · 2022

Comparative effects of pharmacological interventions for the acute and long-term management of insomnia disorder in adults: a systematic review and network meta-analysis.

170 trials (47 950 participants); 154 RCTs (44 089 participants) in the network meta-analysisSystematic review and network meta-analysis of RCTs

Lancet network meta-analysis of 154 RCTs of insomnia drugs: melatonin did not show overall material benefit and was less effective than benzodiazepines and Z-drugs.

Key resultBenzodiazepines, eszopiclone, zolpidem and zopiclone were more efficacious than melatonin, ramelteon and zaleplon (SMD 0·27-0·71)
Studied
Adults with insomnia disorder
Compared with
Placebo and other drugs
Main outcome
Sleep quality, discontinuation, adverse events
Authors' conclusion
Melatonin, ramelteon and non-licensed drugs did not show overall material benefits.
Limitations
Certainty of evidence for many comparisons was low or very low.
PubMed 35843245DOI
~ Mixedmeta-analysisSleep Med Rev · 2022

Efficacy of melatonin for chronic insomnia: Systematic reviews and meta-analyses.

24 randomized controlled trialsSystematic review and meta-analysis of RCTs with age-group subgroups

24 RCTs in chronic insomnia: melatonin was not significantly effective in adults but improved sleep onset and duration in children and adolescents.

Studied
Patients with chronic insomnia (including 4 studies of comorbid insomnia)
Compared with
Placebo
Main outcome
Sleep onset latency, total sleep time, sleep efficiency, sleep quality
Authors' conclusion
Melatonin did not appear effective in adults but might be effective in children and adolescents with chronic insomnia; more studies are needed by age group.
Limitations
Heterogeneity between trials; only one adult study in comorbid insomnia.
PubMed 36179487DOI
✗ Negativesystematic reviewCochrane Database Syst Rev · 2020

Pharmacotherapies for sleep disturbances in dementia.

9 RCTs; melatonin 5 studies, n = 222Cochrane systematic review of drug vs placebo RCTs8 to 10 weeks for melatonin

Cochrane review of people with Alzheimer's dementia: melatonin up to 10 mg had little or no effect on any major sleep outcome; no serious adverse effects reported.

Key resultMelatonin total nocturnal sleep time MD 10.68 minutes (95% CI -16.22 to 37.59; 2 studies, n = 184)
Studied
People with dementia and sleep disturbance
Compared with
Placebo
Main outcome
Total nocturnal sleep time and other sleep outcomes
Authors' conclusion
No evidence of beneficial effects of melatonin (up to 10 mg); low-certainty evidence. Trazodone and orexin antagonists showed some benefit in small trials; larger trials are needed.
Limitations
Few small trials; only four studies systematically assessed adverse effects.
PubMed 33189083DOIFree full text

Verdicts are judged on each paper's own main outcome; grades run from A (strong human evidence) to D (little or none). Details are read from the abstracts, and figures are reproduced only from openly licensed full texts. Not medical advice.