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Moderate evidenceSleep & relaxation

Melatonin

The hormone that regulates the circadian rhythm. Helps you fall asleep faster and is useful for jet lag; the effect is real but modest.

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What the science says

  • Shorter time to fall asleep Moderate evidence

    A meta-analysis of 19 studies showed that melatonin reduces sleep latency (by ~7 minutes on average) and slightly increases total sleep time. The effect is modest but consistent.

  • Jet lag adjustment Moderate evidence

    A Cochrane review concluded that melatonin is remarkably effective at preventing or reducing jet lag on trips crossing several time zones.

Dosage & safety

Studied dose0.5–5 mg, 30–60 minutes before bedtime. Lower doses often work as well as higher ones.
SafetyWell tolerated short-term; may cause daytime drowsiness and vivid dreams. Regulations vary by country: sold over the counter in the US and Canada, but prescription-only or dose-restricted in much of Europe and elsewhere.

How to take it

Timing30-60 minutes before your target bedtime; for jet lag, take it at bedtime in the destination time zone.
With food?Away from a large meal — food delays absorption and blunts the peak.
Worth knowingMore is not better: 0.5-1 mg often works as well as 5-10 mg and is far less likely to leave you foggy in the morning.

Interactions

With medications

  • fluvoxamine and other strong CYP1A2 inhibitors

    Melatonin metabolism is blocked and blood levels rise many-fold, causing next-day grogginess even from a small dose. use the lowest dose or avoid the combination

  • benzodiazepines, z-drugs, sedating antihistamines and alcohol

    Additive sedation and impaired coordination. do not combine without medical advice

  • warfarin and other anticoagulants

    Case reports describe raised INR and bleeding when melatonin is added. tell your anticoagulation clinic before starting

With other supplements

  • valerian, ashwagandha and other sedating supplements

    Additive drowsiness that can carry into the next morning. introduce one at a time rather than stacking a sleep blend

Well-established interactions only — this is not a complete list. Always tell your doctor and pharmacist what you take.

Frequently asked questions

Does melatonin work for sleep?

Melatonin works, but modestly — the evidence is moderate. A meta-analysis of 19 studies found melatonin cuts the time to fall asleep by about 7 minutes on average and slightly increases total sleep time.

How much melatonin should I take?

The melatonin range is 0.5–5 mg, taken 30–60 minutes before bedtime and away from a large meal. More is not better: 0.5–1 mg of melatonin often works as well as 5–10 mg and is less likely to leave you groggy.

Does melatonin work for jet lag?

Yes, with moderate evidence: a Cochrane review found melatonin remarkably effective for trips crossing several time zones. Take melatonin at bedtime in your destination's time zone.

Does melatonin have side effects?

Melatonin is well tolerated short term but can cause daytime drowsiness and vivid dreams. Do not combine melatonin with sedatives or alcohol without medical advice, and tell your anticoagulation clinic if you take warfarin.

Scientific references

Where to buy

NOW Foods, Melatonin, 3 mg, 60 Veg Capsules

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