NutriDex

The Supplement Research Compendium
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Melatonin

The body's sleep-timing hormone, in supplement form.

Strong evidence 🌙Sleep & Mood

✚ Updated · How we grade evidence

Evidence tier
Strong
Research weight
Citations
18 verified / 18
Classification
Sleep & Mood
❝
What the evidence says. Multiple high-quality RCTs / meta-analyses with consistent effects.

What is Melatonin?

Melatonin is a sleep and mood supplement used for faster sleep onset. NutriDex grades the human evidence as Strong. Melatonin is the hormone that signals darkness and regulates the sleep-wake cycle. Supplementation reliably shortens time to fall asleep and is especially effective for circadian problems — jet lag, shift work, and delayed sleep-phase disorder. It is more a chronobiotic (clock-shifter) than a sedative; low doses taken at the right time beat large doses. Long-term safety data are reassuring but limited.

Purported Benefits

✓Faster sleep onset
✓Jet-lag relief
✓Circadian re-timing
✓Shift-work sleep

Evidence by outcome

The same supplement can be well-proven for one use and unproven for another — here is the human evidence graded outcome by outcome.

OutcomeEvidenceEffectStudies
Faster sleep onset (general adults)Dose-response meta-analyses show reduced sleep latency (peak ~4mg, 3h before bed), but a 2022 chronic-insomnia meta-analysis found no significant adult benefit. Mixed ↔ mixed · small 4
Jet lag preventionCochrane review found melatonin effective for preventing and reducing jet lag; older evidence but consistent and clinically endorsed. Moderate ↑ benefit · moderate 1
Circadian re-timing (DSWPD/N24)AASM GRADE guideline and meta-analyses support strategically timed low-dose melatonin for delayed sleep-phase and non-24h disorders as a chronobiotic. Moderate ↑ benefit · moderate 3
Sleep in children/adolescentsMeta-analyses consistently show shortened sleep onset and longer total sleep in children, incl. neurodevelopmental/ASD groups; long-term puberty/bone effects uncertain. Moderate ↑ benefit · moderate 4
Sleep in older adultsMeta-analysis (17 RCTs) found ~21 min more sleep and ~14 min shorter latency vs placebo; modest but a safer option than benzodiazepines. Moderate ↑ benefit · small 2
Postoperative delirium preventionPerioperative meta-analysis found reduced delirium (RR 0.57), but an ICU meta-analysis found no overall benefit; effect appears population-specific. Mixed ↔ mixed · moderate 2
Pediatric overdose/ingestion (harm)CDC surveillance reports a 530% rise in pediatric melatonin ingestions (2012-2021) including hospitalizations and deaths, largely from flavored gummies. Moderate ⚠ risk 2

Dosing & Compounds

Typical Dose
0.5–3 mg, 30–60 min before target bedtime. Lower doses often work as well as higher.
Active Compounds
Melatonin

Safety & Cautions

Safe short-term. Can cause grogginess, vivid dreams. May interact with anticoagulants and sedatives. Educational only — always check with your doctor or pharmacist before combining Melatonin with any medicine.

Melatonin drug interactions

Known or theoretical interactions between Melatonin and common medications — educational, not exhaustive. Always check with your doctor or pharmacist before combining Melatonin with any medicine.

Caution
Sedative-hypnotics & alcohol
Can add to drowsiness and sedation, increasing grogginess and impaired alertness.
Melatonin promotes sleep and may amplify CNS-depressant effects of sedatives and alcohol. NCCIH — Melatonin

Key Studies ★ 18 studies

Meta-analysis Cruz-Sanabria 2024 (dose-response meta-analysis) ✓ PubMed
Dose-response meta-analysis of 26 RCTs (1689 observations) found exogenous melatonin reduces sleep-onset latency and increases total sleep time, with effects peaking around 4 mg taken ~3 hours before bedtime.
Meta-analysis De Crescenzo 2023 (network meta-analysis) ✓ PubMed
Network meta-analysis of 69 RCTs (17,319 adults) ranked melatonin receptor agonists below orexin-receptor antagonists for sleep latency, WASO and efficiency, but found them efficacious for sleep-onset insomnia with good safety.
Meta-analysis Wei 2023 (ASD meta-analysis) ✓ PubMed
Meta-analysis of 4 studies (238 children with autism spectrum disorder) found melatonin shortened sleep-onset latency, reduced night awakenings, and prolonged total sleep time.
Systematic review Handel 2023 (safety systematic review, GRADE) ✓ Full text
Systematic review (22 RCTs, 1350 children/adolescents) found melatonin caused no serious adverse events but a higher rate of non-serious adverse events (RR 1.56, 95% CI 1.01-2.43); long-term effects on puberty/bone remained uncertain, prompting caution.
meta-analysis Shin 2024 (perioperative delirium meta-analysis) ✓ PubMed
Systematic review/meta-analysis of 16 RCTs (1981 surgical patients) found perioperative melatonin reduced postoperative delirium incidence (RR 0.57), with the strongest effect for high-dose melatonin (RR 0.41) and after cardiopulmonary surgery, and no severe adverse events.
meta-analysis Duan 2023 (ICU delirium meta-analysis) ✓ PubMed
Meta-analysis of 6 RCTs (2374 critically ill patients) found melatonin did not significantly reduce overall ICU delirium incidence (OR 0.71, 95% CI 0.46-1.12), but a subgroup of cardiovascular care unit patients showed a significant reduction (OR 0.52, 95% CI 0.37-0.73).
Meta-analysis Low 2022 (older-adults meta-analysis) ✓ PubMed
Systematic review/meta-analysis (17 RCTs, ~2462 subjects, mean age >=55) found melatonin/ramelteon increased objective total sleep time by ~21 min and reduced sleep latency by ~14 min versus placebo, supporting use as a safer option than benzodiazepines.
Meta-analysis Salanitro 2022 (systematic review/meta-analysis) ✓ PubMed
Meta-analysis of 34 RCTs (1998 participants) found melatonin significantly improved sleep-onset latency and total sleep time in children/adolescents with neurodevelopmental disorders and adults with delayed sleep-phase disorder, with tolerability similar to placebo.
meta-analysis Agahi 2022 (antipsychotic metabolic meta-analysis) ✓ PubMed
Meta-analysis of 5 RCTs (248 patients on antipsychotics) found melatonin/ramelteon improved non-anthropometric metabolic syndrome components versus placebo, lowering systolic blood pressure by ~3.3 mmHg and triglycerides by ~9.8 mg/dL, with no effect on weight or waist circumference.
Meta-analysis Choi et al. (Sleep Med Rev) 2022 ✓ PubMed
Systematic review/meta-analysis of 24 RCTs in chronic insomnia: melatonin was NOT significantly effective in adults for sleep onset latency, total sleep time, or sleep efficiency, but significantly improved sleep onset latency and total sleep time in children/adolescents. In comorbid insomnia it improved sleep onset latency across age groups.
Agency / regulator CDC MMWR (Lelak) 2024 ✓ Source
Notes from the Field: U.S. emergency department visits for unsupervised pediatric melatonin ingestion rose sharply during 2019-2022, with flavored products (gummies/chewables) involved in about half of visits.
Meta-analysis Wei et al. (Sleep Med) 2019 ✓ PubMed
Meta-analysis of 7 RCTs (387 children/adolescents with sleep-onset insomnia): melatonin advanced sleep onset time by 0.62 h (95% CI -0.80 to -0.45), advanced dim-light melatonin onset by 0.82 h, reduced sleep onset latency by 0.36 h, and increased total sleep time by 0.38 h vs placebo, with no significant difference in dropouts.
Meta-analysis Ferracioli-Oda 2013 meta-analysis ✓ PubMed
Reduced sleep latency and increased total sleep time.
Agency / regulator Lelak 2022 (CDC MMWR) ✓ Source
Pediatric melatonin ingestions reported to U.S. poison control centers increased 530% from 2012 to 2021 (8,337 to 52,563 annually), including reports of hospitalization and two deaths.
Cochrane review Herxheimer 2002 (Cochrane) ✓ PubMed
Effective for preventing and reducing jet lag.
Guideline Auger et al. AASM Clinical Practice Guideline 2015 ✓ PubMed
American Academy of Sleep Medicine GRADE-based guideline positively endorses strategically timed melatonin for delayed sleep-wake phase disorder (DSWPD), blind adults with non-24-hour disorder (N24SWD), and children/adolescents with irregular sleep-wake rhythm disorder plus comorbid neurological disorders; recommends AGAINST melatonin in demented elderly.
RCT Wade et al. (Circadin trial) 2007 ✓ PubMed
Landmark double-blind RCT, 354 primary insomnia patients aged 55-80: prolonged-release melatonin 2 mg nightly improved concomitant sleep quality plus morning alertness (responder rate 26% vs 15% placebo; p=0.014) and shortened sleep latency (-24.3 vs -12.9 min; p=0.028), with improved quality of life and a placebo-like safety profile.
Review Auld 2017 review ✓ PubMed
Beneficial for delayed sleep-phase and circadian disorders.
18 sources cited · 18 verified Search all studies on PubMed ↗

Common questions about Melatonin

What is Melatonin used for?

Melatonin is most often taken for Faster sleep onset, Jet-lag relief, Circadian re-timing, Shift-work sleep. The body's sleep-timing hormone, in supplement form.

Does Melatonin work — what does the evidence say?

Strong evidence. Multiple high-quality RCTs / meta-analyses with consistent effects. Melatonin is the hormone that signals darkness and regulates the sleep-wake cycle. Supplementation reliably shortens time to fall asleep and is especially effective for circadian problems — jet lag, shift work, and delayed sleep-phase disorder. It is more a chronobiotic (clock-shifter) than a sedative; low doses taken at the right time beat large doses. Long-term safety data are reassuring but limited.

What is the typical dose of Melatonin?

0.5–3 mg, 30–60 min before target bedtime. Lower doses often work as well as higher.

Is Melatonin safe? Any cautions or side effects?

Safe short-term. Can cause grogginess, vivid dreams. May interact with anticoagulants and sedatives.

How many studies support Melatonin?

NutriDex cites 18 sources for Melatonin, graded "Strong".

Does Melatonin interact with any medications?

Yes — known or theoretical interactions include: Sedatives (benzodiazepines, opioids, alcohol) (caution). This is educational and not exhaustive; always check with your doctor or pharmacist before combining Melatonin with any medicine.

Cite this page
APA

Peh, D. (2026). Melatonin: Benefits, Dosage, Side Effects & Evidence. NutriDex — The Supplement Research Compendium. Retrieved 26 Jun 2026, from https://nutridex.info/s/melatonin

BibTeX
@misc{nutridex_melatonin,
  author       = {Peh, Daryl},
  title        = {Melatonin: Benefits, Dosage, Side Effects \& Evidence},
  year         = {2026},
  howpublished = {NutriDex --- The Supplement Research Compendium},
  url          = {https://nutridex.info/s/melatonin},
  note         = {Reviewed by Dr Daryl Peh, MBBS Singapore, MMed FM. Accessed 2026-06-26}
}

For medical claims, citing the underlying primary studies linked above is preferred. NutriDex is an educational reference, not medical advice.

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