Skip to main content
Supplement ScienceSupplementScience

Melatonin Side Effects & Safety

Evidence:Strong
·

This content is for informational purposes only and does not constitute medical advice. Statements about dietary supplements have not been evaluated by the FDA and are not intended to diagnose, treat, cure, or prevent any disease. Individual results may vary — consult your healthcare provider before starting any supplement. Full disclaimer

Safety Profile

Overall safety rating: Generally Safe

Potential Side Effects

  • Generally very well tolerated at standard doses
  • Morning drowsiness or grogginess (more common at higher doses >3mg)
  • Vivid dreams or nightmares (uncommon)
  • Headache (uncommon)
  • Mild dizziness (rare)
  • Temporary feelings of depression (rare, at higher doses)
  • May suppress endogenous production temporarily with long-term high-dose use (though evidence for this is weak)

Drug & Supplement Interactions

  • Sedative medications (benzodiazepines, zolpidem) — additive sedation effects, use caution
  • Anticoagulants (warfarin) — melatonin may increase bleeding risk
  • Immunosuppressants — melatonin has immunostimulatory properties that may counteract immunosuppression
  • Diabetes medications — melatonin may affect blood sugar levels
  • Fluvoxamine — strongly inhibits melatonin metabolism (CYP1A2), dramatically increasing melatonin levels
  • Caffeine — may reduce melatonin production; avoid caffeine after 2 PM

Maximum Dose

Do not exceed: 10mg/day (higher doses are not more effective and may cause morning grogginess)

Looking for a well-tested Melatonin?
All our top picks are third-party verified for purity
Full Melatonin Guide

References

  1. Meta-analysisFerracioli-Oda E, Qawasmi A, Bloch MH (2013). Meta-analysis: melatonin for the treatment of primary sleep disorders. PLoS ONE. DOI PubMed
  2. ReviewHerxheimer A, Petrie KJ (2002). Melatonin for the prevention and treatment of jet lag. Cochrane Database of Systematic Reviews. DOI PubMed
  3. Meta-analysisBrzezinski A, Vangel MG, Wurtman RJ, et al. (2005). Effects of exogenous melatonin on sleep: a meta-analysis. Sleep Medicine Reviews. DOI PubMed
  4. RCTZhdanova IV, Wurtman RJ, Regan MM, Taylor JA, Shi JP, Leclair OU (2001). Melatonin treatment for age-related insomnia. Journal of Clinical Endocrinology & Metabolism. DOI PubMed
  5. Tang BHY, Manalo J, Chowdhury SR, Aldrich JM, et al. (2025). Melatonin Use in the ICU: A Systematic Review and Meta-Analysis.. Critical care medicine. DOI PubMed
  6. Daliri AS, Goudarzi N, Harati A, Kabir K (2025). Melatonin as a Novel Drug to Improve Cardiac Function and Quality of Life in Heart Failure Patients: A Systematic Review and Meta-Analysis.. Clinical cardiology. DOI PubMed
  7. Meta-analysisCruz-Sanabria F, Bruno S, Crippa A, Frumento P, et al. (2024). Optimizing the Time and Dose of Melatonin as a Sleep-Promoting Drug: A Systematic Review of Randomized Controlled Trials and Dose-Response Meta-Analysis.. Journal of pineal research. DOI PubMed
Show 3 more references
  1. Terao I, Kodama W (2024). Comparative Efficacy, Tolerability, and Acceptability of Donanemab, Lecanemab, Aducanumab, Melatonin, and Aerobic Exercise for a Short Time on Cognitive Function in Mild Cognitive Impairment and Mild Alzheimer's Disease: A Systematic Review and Network Meta-Analysis.. Journal of Alzheimer's disease : JAD. DOI PubMed
  2. Liu Z, Zhu J, Shen Z, Ling Y, et al. (2024). Melatonin as an add-on treatment for epilepsy: A systematic review and meta-analysis.. Seizure. DOI PubMed
  3. Li Y, Sun X, Wang M, Jiang Y, et al. (2024). Meta-analysis and machine learning reveal the antiobesity effects of melatonin on obese rodents.. Obesity reviews : an official journal of the International Association for the Study of Obesity. DOI PubMed