Melatonin

A circadian-clock hormone taken most often for jet lag and sleep timing.

Supplements

Research records

Historical source snapshot. Not freshly verified, not a recommendation. Study findings, community accounts and app defaults are not interchangeable.

Publication suitability · 2026-10-15: Historical reference only; not a clinical verification. Clinical, regulatory, efficacy, safety and dose claims are not independently established by this review.

Melatonin

A circadian-clock hormone taken most often for jet lag and sleep timing.

Evidence category: Systematic review. This describes the source category, not approval or certainty.

Regulatory statement in source: Not separately recorded; do not infer approval from the evidence category.

Melatonin is a hormone produced by the pineal gland that helps regulate the body's internal circadian clock in response to darkness. Synthetic melatonin is sold as an over-the-counter dietary supplement in the United States, while several other countries regulate it as a prescription medicine, and it has been studied most extensively for jet lag and circadian sleep-timing disorders.

Benefits reported in the imported source

Reduces jet lag symptoms after long eastward flights in the majority of trials reviewed
Shortens time to sleep onset in circadian sleep-timing disorders
Short-term use shows a low rate of side effects across trial populations

Risks and limits

Long-term safety data are limited
Independent testing has found product content varying from label claims
Case reports describe interactions in people with epilepsy or on warfarin

Source bottom line: Evidence for jet lag is unusually strong for a supplement, resting on multiple randomized trials, while evidence for chronic insomnia remains weak by comparison.

Uncertainty: Reference information only. Not medical advice.

Study protocols — reports, not instructions

Airline passengers, airline staff and military personnel crossing five or more time zones, pooled across ten randomized trials

Reported regimen: Oral melatonin doses between 0.5 mg and 5 mg administered close to target bedtime at the destination (22:00 to midnight); doses above 5 mg showed no added benefit and a 2 mg slow-release formulation was less effective
Duration: Single doses taken near destination bedtime, pooled across ten trials
Reported outcome: Nine of ten trials found reduced jet lag symptoms after flights crossing five or more time zones, with a calculated number needed to treat of two; side effects were infrequent
Source: Melatonin for preventing and treating jet lag - Cochrane Database of Systematic Reviews (PubMed)

Claim provenance

evidence.json#/catalog:supplement:melatonin/protocols/0

Community and practice descriptions

Accounts of a practice are not evidence of safety or effectiveness. Words such as “standard”, “safe” or “recommended” describe the source account, not verified consensus or this wiki’s advice. Commercial and self-published citations are retained for traceability, not vendor endorsement or independent clinical corroboration.

Historical research outcome: no-verified-description · 2026-10-06

No suitable community description was independently verified in these checks. The entry remains empty; this does not establish that no practice exists elsewhere.

https://www.nccih.nih.gov/health/melatonin: no-practice-description — This retrieved source was checked, but no suitable community description was independently verified. Research regimens, expert advice, product identity and efficacy claims were not repurposed.
https://www.cdc.gov/yellow-book/hcp/preparing-international-travelers/complementary-and-integrative-health-approaches.html: no-practice-description — This retrieved source was checked, but no suitable community description was independently verified. Research regimens, expert advice, product identity and efficacy claims were not repurposed.

Pharmacokinetic context

Historical half-life estimate: 0.9 hours. Andersen et al. 2016, BMC Pharmacol Toxicol, PMID 26893170 — immediate-release oral, 10 mg dose; ranges 40-104 min depending on formulation and physiological state Population/route context and estimates may differ. This is not a schedule or a verified human dosing rule.

Source references

Snapshot provenance

Source ID: catalog:supplement:melatonin. Commit: adc7684614f9439b41d91a3312b62e7982c7e20e. Review state: historical-not-reverified. Authored links are retained separately from the canonical evidence links in the public data. App templates/defaults and rejected drafts are archived, not deployed.

Related entries and components

None listed.