Does melatonin actually help you sleep?

What we can tell you today: how thoroughly this has been studied.

Thoroughly studied

11 studies, of which 4 bring together the results of several trials in people. This is as strong as evidence gets.

5 Repeated evidence 4 studies

4 Large controlled trial 6 studies

3 Small study in people 1 study

This says how thoroughly something has been studied — not whether it works for you. What each study actually found is in the study itself, and in the plain-language write-ups we are adding.

Appears under: Sleep, energy and the brain · Menopause and hormones

The studies

5 Repeated evidence Optimizing the Time and Dose of Melatonin as a Sleep-Promoting Drug: A Systematic Review of Randomized Controlled Trials and Dose-Response Meta-Analysis.
2024 · Journal of pineal research · 26 participants
5 Repeated evidence Efficacy of melatonin for chronic insomnia: Systematic reviews and meta-analyses.
2022 · Sleep medicine reviews
5 Repeated evidence Effects of melatonin on postoperative sleep quality: a systematic review, meta-analysis, and trial sequential analysis.
2023 · Canadian journal of anaesthesia = Journal canadien d'an · 516 participants
5 Repeated evidence The use of prolonged-release melatonin in circadian medicine: a systematic review.
2024 · Minerva medica
4 Large controlled trial The effect of melatonin on sleep quality and cognitive function of individuals undergoing hemodialysis.
2026 · Sleep medicine · 102 participants
4 Large controlled trial An investigation into an evening intake of a saffron extract (affron®) on sleep quality, cortisol, and melatonin concentrations in adults with poor sleep: a randomised, double-blind, placebo-controlled, multi-dose study.
2021 · Sleep medicine · 120 participants
4 Large controlled trial Effect of melatonin on postoperative cognitive function in elderly patients submitted to transurethral resection of the prostate under spinal anesthesia.
2024 · Clinics (Sao Paulo, Brazil) · 118 participants
4 Large controlled trial Melatonin agonist tasimelteon (HETLIOZ®) improves sleep in patients with primary insomnia: A multicenter, randomized, double-blind, placebo-controlled trial.
2025 · PloS one · 322 participants
4 Large controlled trial Melatonin agonist tasimelteon (VEC-162) for transient insomnia after sleep-time shift: two randomised controlled multicentre trials.
2009 · Lancet (London, England) · 106 participants
4 Large controlled trial Soy isoflavones and melatonin for the relief of climacteric symptoms: a multicenter, double-blind, randomized study.
2004 · Maturitas · 262 participants
3 Small study in people Melatonin and sleep parameters in infertile women with endometriosis: first results from the triple-blind randomized controlled trial of administration of melatonin in chronic pelvic pain and sleep disturbance.
2025 · PloS one