Condition
    Moderate Evidence
    Effectiveness 3/5

    Melatonin for Insomnia

    For true insomnia, melatonin's effect is modest — meta-analyses show sleep onset shortened by roughly seven to twelve minutes. CBT for insomnia is substantially more effective and is the recommended first-line treatment.

    Overview

    For true insomnia, melatonin's effect is modest — meta-analyses show sleep onset shortened by roughly seven to twelve minutes. CBT for insomnia is substantially more effective and is the recommended first-line treatment.

    Verdict

    Mixed evidence

    Cheap and safe to try at a low dose, but do not expect much. If insomnia is persistent, CBT-I is the intervention with the real evidence.

    How It Works

    Melatonin acts on MT1 and MT2 receptors in the suprachiasmatic nucleus, dampening the evening circadian alerting signal and shifting circadian phase. It does not act on GABA receptors and therefore does not sedate. In primary insomnia, the alerting signal is often not the limiting problem — hyperarousal is — which explains the modest effect size.

    Dosing & Protocol

    Typical dose

    Recommended dose
    0.5-1 mg, 30-60 minutes before bed
    Expected timeframe
    1-14 days

    Protocol

    form
    Immediate-release, third-party tested
    duration
    2 weeks before judging
    co factor
    Pair with CBT-I, which has far larger effects
    titration
    1 mg after a week if needed; higher rarely helps
    starting dose
    0.5 mg, 30-60 minutes before bed in dim light

    Evidence

    What the studies say

    Meta-analyses pooling randomised trials in primary insomnia find melatonin reduces sleep onset latency by approximately seven to twelve minutes and increases total sleep time by roughly eight to twenty minutes versus placebo, with small improvements in subjective sleep quality. Effects are larger in older adults and in delayed sleep phase disorder. By comparison, cognitive behavioural therapy for insomnia produces substantially larger and more durable improvements and is recommended first-line by major guidelines. Prolonged-release melatonin is licensed for insomnia in over-55s in several countries on the basis of these modest but consistent effects.

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

    Score: 8/10
    2013
    meta_analysis
    n=1683

    Ferracioli-Oda E, et al.

    This meta-analysis demonstrates that melatonin decreases sleep onset latency, increases total sleep time and improves overall sleep quality.

    View source

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

    Score: 8/10
    2022
    meta_analysis

    Melatonin produced small improvements in sleep onset latency and sleep quality in chronic insomnia.

    View source

    Efficacy of prolonged release melatonin in insomnia patients aged 55-80 years: quality of sleep and next-day alertness outcomes

    Score: 7/10
    2007
    rct
    n=170

    Wade AG, Ford I, Crawford G +4 more

    Prolonged-release melatonin significantly improved sleep quality and morning alertness versus placebo, with no rebound insomnia.

    View source

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

    Score: 9/10
    2022
    systematic_review
    n=47950

    De Crescenzo F, et al.

    Melatonin, ramelteon, and non-licensed drugs did not show overall material benefits.

    View source

    Prolonged-release melatonin improves sleep quality and morning alertness in insomnia patients aged 55 years and older and has no withdrawal effects

    Score: 7/10
    2007
    rct
    n=170

    Lemoine P, et al.

    PR-melatonin is the first drug shown to significantly improve quality of sleep and morning alertness in primary insomnia patients aged 55 years and older.

    View source

    The effect of prolonged-release melatonin on sleep measures and psychomotor performance in elderly patients with insomnia

    Score: 7/10
    2009
    rct
    n=40

    Luthringer R, Muzet M, Zisapel N +1 more

    the PRM group had significantly shorter sleep onset latency (9 min; P = 0.02) compared with the placebo group

    View source

    Melatonin for sleep disorders

    Score: 8/10
    2013
    meta_analysis
    n=1683

    Ferracioli-Oda, E., Qawasmi, A.

    Melatonin reduced sleep onset latency and increased total sleep time and sleep quality across primary sleep disorders.

    View source

    The effect of magnesium supplementation on primary insomnia in elderly: a double-blind placebo-controlled clinical trial

    Score: 5/10
    2012n=46

    Abbasi B, Kimiagar M, Sadeghniiat K +3 more

    Magnesium significantly increased sleep time and sleep efficiency and reduced Insomnia Severity Index scores, sleep onset latency and early morning awakening compared with placebo. Serum renin and melatonin increased and serum cortisol decreased in the magnesium group.

    View source

    The Effect of Magnesium Supplementation on Primary Insomnia in Elderly: A Double-Blind Placebo-Controlled Clinical Trial

    Score: 7/10
    2012
    rct
    n=46

    Abbasi B, Kimiagar M, Sadeghniiat K +3 more

    Magnesium supplementation significantly improved PSQI scores (p<0.05) Significant increase in sleep time by 42 minutes (p<0.001) Improved sleep efficiency from 74% to 85% (p<0.001) Reduced early morning awakening frequency (p<0.01) Increased serum melatonin concentration (p<0.05) Decreased serum cortisol levels (p<0.05) Reduced sleep onset latency by 17 minutes

    View source

    Evidence for the efficacy of melatonin in the treatment of primary adult sleep disorders

    Score: 9/10
    2017
    systematic_review

    Auld F, Maschauer EL, Morrison I +2 more

    Melatonin showed the strongest evidence for reducing sleep onset latency in primary insomnia and for circadian rhythm disorders.

    View source

    Efficacy of melatonin for sleep disturbance in middle-aged primary insomnia: a double-blind, randomised clinical trial

    Score: 6/10
    2020
    rct

    Melatonin improved sleep quality and continuity versus placebo in middle-aged primary insomnia.

    View source

    The Effect of Magnesium Supplementation on Primary Insomnia in Elderly

    Score: 7/10
    2012
    rct
    n=46

    Abbasi B, Kimiagar M, Sadeghniiat K +1 more

    Magnesium supplementation significantly improved PSQI scores (p<0.05) Significant increase in sleep time by 42 minutes (p<0.001) Improved sleep efficiency from 74% to 85% (p<0.001) Reduced early morning awakening frequency (p<0.01) Increased serum melatonin concentration (p<0.05) Decreased serum cortisol levels (p<0.05) Reduced sleep onset latency by 17 minutes

    View source

    Effects of tryptophan-enriched cereals consumed at breakfast and dinner on sleep, mood and melatonin in elderly people

    Score: 5/10
    2013
    crossover
    n=35

    Bravo R, Matito S, Cubero J

    Tryptophan-enriched cereals increased sleep efficiency, actual sleep time and urinary melatonin while reducing depression and anxiety scores in older adults.

    View source

    Efficacy and safety of exogenous melatonin for secondary sleep disorders and sleep disorders accompanying sleep restriction: meta-analysis

    Score: 9/10
    2006
    meta_analysis

    Buscemi N, Vandermeer B, Hooton N +6 more

    Melatonin did not produce a clinically meaningful reduction in sleep onset latency in secondary sleep disorders or sleep restriction.

    View source

    The efficacy and safety of exogenous melatonin for primary sleep disorders: a meta-analysis

    Score: 9/10
    2005
    meta_analysis

    Buscemi N, Vandermeer B, Hooton N +6 more

    Melatonin reduced sleep onset latency by a small but statistically significant amount, with no significant effect on sleep efficiency or total sleep time.

    View source

    The effect of melatonin, magnesium, and zinc on primary insomnia in long-term care facility residents in Italy: a double-blind, placebo-controlled clinical trial

    Score: 7/10
    2011
    rct
    n=43

    Rondanelli M, et al.

    The administration of nightly melatonin, magnesium, and zinc appears to improve the quality of sleep and the quality of life in long-term care facility residents with primary insomnia.

    View source

    Dose finding of melatonin for chronic idiopathic childhood sleep onset insomnia: an RCT

    Score: 8/10
    2010
    rct
    n=72

    van Geijlswijk IM, van der Heijden KB, Egberts ACG +2 more

    All melatonin doses advanced sleep onset and dim light melatonin onset compared with placebo, with no dose-response relationship.

    View source

    The effect of magnesium supplementation on primary insomnia in elderly: A double-blind placebo-controlled clinical trial

    Score: 7/10
    2012
    rct
    n=46

    Abbasi B, Kimiagar M, Sadeghniiat K +3 more

    Magnesium supplementation significantly improved PSQI scores (p<0.05) Significant increase in sleep time by 42 minutes (p<0.001) Improved sleep efficiency from 74% to 85% (p<0.001) Reduced early morning awakening frequency (p<0.01) Increased serum melatonin concentration (p<0.05) Decreased serum cortisol levels (p<0.05) Reduced sleep onset latency by 17 minutes

    View source

    Safety

    Caveats

    Not habit-forming, but persistent insomnia beyond three months warrants proper assessment rather than indefinite supplementation. Avoid in pregnancy and review with a doctor if on anticoagulants.

    Less likely to help if

    People with hyperarousal-type insomnia, untreated sleep apnoea, restless legs, chronic pain or significant anxiety typically see no benefit. Those already on high doses feeling groggy usually improve by lowering the dose.

    Medical Disclaimer

    The information provided on this website is for educational and informational purposes only and is not intended as a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition or before starting any supplement regimen.

    Individual results may vary. The statements on this website have not been evaluated by the Food and Drug Administration. Products and information are not intended to diagnose, treat, cure, or prevent any disease.