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Sleep · Explainer

Melatonin: What It Does, and What It Does Not Do

Sleep illustration

Key takeaways

  • Melatonin is a darkness signal, not a sedative.
  • Best evidence: jet lag and body-clock shifts, not general insomnia.
  • Small, earlier doses beat large, late ones.
  • Quality varies; medical advice applies for medications, pregnancy and children.

Melatonin is among the most-purchased supplements on Earth, and among the most misunderstood. It is not a sleeping pill, and using it like one explains most disappointments.

What melatonin actually is

Melatonin is a hormone your brain releases as darkness falls, a signal that night has begun, not a sedative. Supplemental melatonin mainly shifts the timing of your body clock, which is why it shines for jet lag and shifted schedules and underwhelms for ordinary tossing and turning.

What the evidence shows

Studies show modest benefits: falling asleep a few minutes faster on average, with the clearest wins in circadian problems like jet lag. Timing and dose matter more than strength; small doses taken a few hours before target bedtime often beat large doses at midnight. More is not better, and product quality varies widely between brands.

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Sensible use

Used occasionally and correctly, melatonin is considered low-risk for most adults short-term. It is not a fix for insomnia driven by stress, caffeine or irregular schedules, where behavioural approaches win. People on medications, pregnant women and children's use belong in a doctor's conversation.

This article is for general informational purposes only and is not medical advice. Always consult a qualified healthcare professional about your individual situation, and never start or stop a medication without your doctor. See our Medical Disclaimer.