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What is the maximum safe dosage for melatonin?

Medically reviewed by Carmen Pope, BPharm. Last updated on Aug 5, 2025.

Official Answer by Drugs.com

There is no FDA-established maximum melatonin dose for adults, but research indicates that 0.5 mg to 5 mg is the optimal safe and effective range. Most sleep experts recommend starting with the lowest effective dose, typically 0.5 to 1 mg. Dosages higher than 5 mg appear to be no more effective than dosages less than 5 mg. Note that melatonin is not usually recommended for children aged less than 3, unless under the supervision of a doctor.

Melatonin is regulated by the FDA in the United States as a dietary supplement but is not subject to the same regulations as medicines. This means the FDA does not regulate its purity or dosage accuracy, meaning there is no assurance that the melatonin content listed on the label actually matches what's contained in each capsule.

The CDC has reported that 71% of melatonin supplements do not match their label claims with up to 465% variation between batches of the same product. In 2020, melatonin was the most frequently ingested substance reported to poison control centers. Over the 10 years from 2012-2021, melatonin ingestions by children increased 530%, with the largest spike in increases occurring during the COVID-19 pandemic. 94.3% of these ingestions were accidental.

There have also been instances where some dietary supplements have been contaminated with heavy metals or other drugs. If you are taking melatonin or giving melatonin to your child always purchase Melatonin from a reputable company that follows Good Manufacturing Practices (GMP) and always give the lowest possible dose for the shortest time. Keep any melatonin you have in your home in a locked or high cupboard, out of reach of children.

Recommended Melatonin Dosage Guidelines:

Daily doses of 0.5 and 5 mg have been found to have similar effectiveness, except there was some evidence found by a Cochrane review that people fall asleep faster and sleep better with the 5 mg dose.

Related questions

Is taking 30 mg melatonin safe?

Taking 30 mg of melatonin would not be considered safe by sleep medicine experts. This extremely high dose significantly exceeds recommended guidelines and can cause serious side effects such as:

A Cochrane review confirmed that melatonin doses above 5 mg used for jet lag provided no additional sleep benefits compared to lower doses, making high-dose supplementation both unnecessary and potentially harmful.

Long-term Effects of Melatonin

Research on taking melatonin for long periods of time is limited. Some studies have associated prolonged high-dose melatonin supplementation with:

References

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