Supplement Forms/Alternate Names:
Melatonin is a hormone made by the body that helps regulate sleep. It can be taken as a pill, powder, or extract. It can also be applied to the skin and injected into the bloodstream by a healthcare provider. Melatonin has been used to ease anxiety, improve sleep, and lower blood pressure.
1 to 10 milligrams as needed
What Research Shows
- Alzheimer disease —likely to improve sleep quality A1-A5
- Anxiety —likely to ease short term anxiety B1
- Autism —likely to improve sleep and daytime behavior C1
- Cancer treatment support —likely to ease side effects D1, D2
- Emergency agitation after general anesthesia —likely to improve sleep quality and emergence behavior H1, H2
- High blood pressure —likely to lower nighttime blood pressure J1, J2
- Jet lag—likely to reduce symptoms K1
- Metabolic disorders —likely to lower blood glucose levels and improve insulin sensitivity L1
- Neonatal sepsis —likely to improve sepsis status N1
- Parkinson disease —likely to improve sleep quality O1
- Secondary sleep disorders —likely to lower the length of time it takes to fall asleep and likely to increase total sleep time Q1
- Sleep disorders —likely to improve sleep R1-R3
May Not Be Effective
- Dysmenorrhea —may not provide benefit G1
Unlikely to Be Effective
- Depression —unlikely to ease depressive symptoms F1
- Sleep disturbances —unlikely to ease sleep disturbances in night shift workers R
Not Enough Data to Assess
Editorial process and description of evidence categories can be found at EBSCO NAT Editorial Process.
It is likely safe to take melatonin in small doses for a short time, but headache and daytime drowsiness may happen. Not enough studies have been done to say whether it is safe to take for a long period. It is also not known whether it is safe to take by women who are pregnant, trying to become pregnant, or breastfeeding.
Talk to your doctor about any supplements or therapy you would like to use. Some can interfere with treatment or make conditions worse, such as:
- Melatonin contains lactose. People with problems digesting lactose should talk to their doctors before taking melatonin.
- People who have liver problems, immune diseases, kidney problems, or neurological problems should talk to their doctor before taking melatonin.
A. Alzheimer Disease
A1. McCleery J, Cohen DA, et al. Pharmacotherapies for sleep disturbances in Alzheimer's disease. Cochrane Database Syst Rev. 2014 Mar 21;(3):CD009178.
A2. Xu J, Wang LL, et al. Melatonin for sleep disorders and cognition in dementia: a meta-analysis of randomized controlled trials. Am J Alzheimers Dis Other Demen. 2015 Aug;30(5):439-447.
A3. McCleery J, Cohen DA, et al. Pharmacotherapies for sleep disturbances in dementia. Cochrane Database Syst Rev. 2016 Nov 16;11:CD009178.
A4. Zhang W, Chen XY, et al. Exogenous melatonin for sleep disorders in neurodegenerative diseases: a meta-analysis of randomized clinical trials. Neurol Sci. 2016;37(1):57-65.
A5. Wang YY, Zheng W, et al. Meta-analysis of randomized, double-blind, placebo-controlled trials of melatonin in Alzheimer’s disease. Int J Geriatr Psychiatry. 2017;32(1):50-57.
B1. Hansen MV, Halladin NL, et al. Melatonin for pre- and postoperative anxiety in adults. Cochrane Database Syst Rev. 2015;(4):CD009861.
C. Autism Spectrum Disorders
C1. Rossignol DA, Frye RE. Melatonin in autism spectrum disorders: a systematic review and meta-analysis. Dev Med Child Neurol. 2011;53(9):783-792.
D. Cancer Treatment Support
D1. Seely D, Wu P, et al. Melatonin as adjuvant care with and without chemotherapy: a systematic review and meta-analysis of randomized trials. Integr Cancer Ther. 2012;11(4):293-303.
D2. Wang YM, Jin BZ, et al. The efficacy and safety of melatonin in concurrent chemotherapy or radiotherapy for solid tumors: a meta-analysis of randomized controlled trials. Cancer Chemother Pharmacol. 2012 May;69(5):1213-1220.
E1. Siddiqi N, Harrison JK, Clegg A, Teale EA, Young J, Taylor J, Simpkins SA. Interventions for preventing delirium in hospitalised non-ICU patients. Cochrane Database Syst Rev. 2016 Mar 11;3:CD005563.
E2. Chen S, Shi L, et al. Exogenous Melatonin for Delirium Prevention: a Meta-analysis of Randomized Controlled Trials. Mol Neurobiol. 2016 Aug;53(6):4046-4053.
F1. Hansen MV, Danielsen AK, et al. The therapeutic or prophylactic effect of exogenous melatonin against depression and depressive symptoms: a systematic review and meta-analysis. Eur Neuropsychopharmacol. 2014 Nov;24(11):1719-1728.
G1. Pattanittum P, Kunyanone N, et al. Dietary supplements for dysmenorrhoea. Cochrane Database Syst Rev. 2016 Mar 22;3:CD002124.
H. Emergence Agitation After General Anesthesia
H1. Andersen LP, Werner MU, et al. A systematic review of peri-operative melatonin. Anaesthesia. 2014 Oct;69(10):1163-71.
H2. Mihara T, Nakamura N, et al. Effects of melatonin premedication to prevent emergence agitation after general anaesthesia in children: A systematic review and meta-analysis with trial sequential analysis. Eur J Anaesthesiol. 2015 Dec;32(12):862-871.
I1. Brigo F, Igwe SC, et al. Melatonin as add-on treatment for epilepsy. Cochrane Database Syst Rev. 2016;(8):CD006967.
J. High Blood Pressure
J1. Grossman E, Laudon M, et al. Effect of melatonin on nocturnal blood pressure: meta-analysis of randomized controlled trials. Vasc Health Risk Manag. 2011;7:577-584.
J2. Hadi A, Ghaedi E, et al. Effects of Melatonin Supplementation On Blood Pressure: A Systematic Review and Meta-Analysis of Randomized Controlled Trials. Horm Metab Res. 2019 Mar;51(3):157-164.
K. Jet Lag
K1. Tortorlo F, Farren F, et al. Is melatonin useful for jet lag? Medwave. 2015;15(3):e6343.
L. Metabolic Disorders
L1. Doosti-Irani A, Ostadohammadi V, et al. The Effects of Melatonin Supplementation on Glycemic Control: A Systematic Review and Meta-Analysis of Randomized Controlled Trials. Horm Metab Res. 2018;50(11):783-790.
M1. Long R, ZhuY, et al. Therapeutic rold of melatonin in migraine prophylaxis: A systematic review. Medicine (Baltimore). 2019;98(3):e14099.
N. Neonatal Sepsis
N1. Henderson R, Kim S, et al. Use of melatonin as adjunctive therapy in neonatal sepsis: A systematic review and meta-analysis. Complement Ther Med. 2018 Aug;39:131-136.
O. Parkinson Disease
O1. Zhang W, Chen XY, et al. Exogenous melatonin for sleep disorders in neurodegenerative diseases: a meta-analysis of randomized clinical trials. Neurol Sci. 2016;37(1):57-65.
P. Seasonal Affective Disorder
P1. Kaminski-Hartenthaler A, Nussbaumer B, et al. Melatonin and agomelatine for preventing seasonal affective disorder. Cochrane Database Syst Rev. 2015;(11):CD011271.
Q. Secondary Sleep Disorders
Q1. Li T, Jiang S, et al. Exogenous melatonin as a treatment for secondary sleep disorders: A systematic review and meta-analysis. Front Neuroendocrinol. 2019 Jan;52:22-28.
R. Sleep Disorders
R1. Ferracioli-Oda E, Qawasmi A, et al. Meta-analysis: melatonin for the treatment of primary sleep disorders. PLoS One. 2013 May 17;8(5):e63773.
R2. Auld F, Maschauer EL, et al. Evidence for the efficacy of melatonin in the treatment of primary adult sleep disorders. Sleep Med Rev. 2017;34:10-22.
R3. Abdelgadir IS, Gordon MA, et al. Melatonin for the management of sleep problems in children with neurodevelopmental disorders: a systematic review and meta-analysis. Arch Dis Child. 2018 Dec;103(12):1155-1162.
S. Sleep Disturbances
S1. Liira J, Verbeek JH, et al. Pharmacological interventions for sleepiness and sleep disturbances caused by shift work. Cochrane Database Syst Rev. 2014 Aug 12;(8):CD009776.
Last reviewed March 2020 by EBSCO NAT Review Board Eric Hurwitz, DC Last Updated: 6/29/2020