BACKGROUND: Exogenous melatonin has been increasingly used in the management of sleep disorders.
PURPOSE: To conduct a systematic review of the efficacy and safety of exogenous melatonin in the management of primary sleep disorders.
DATA SOURCES: A number of electronic databases were searched. We reviewed the bibliographies of included studies and relevant reviews and conducted hand-searching.
STUDY SELECTION: Randomized controlled trials (RCTs) were eligible for the efficacy review, and controlled trials were eligible for the safety review.
DATA EXTRACTION: One reviewer extracted data, while the other verified data extracted. The Random Effects Model was used to analyze data.
DATA SYNTHESIS: Melatonin decreased sleep onset latency (weighted mean difference [WMD]: −11.7 minutes; 95% confidence interval [CI]: −18.2, −5.2)); it was decreased to a greater extent in people with delayed sleep phase syndrome (WMD: −38.8 minutes; 95% CI: −50.3, −27.3; n=2) compared with people with insomnia (WMD: −7.2 minutes; 95% CI: −12.0, −2.4; n=12). The former result appears to be clinically important. There was no evidence of adverse effects of melatonin.
CONCLUSIONS: There is evidence to suggest that melatonin is not effective in treating most primary sleep disorders with short-term use (4 weeks or less); however, additional large-scale RCTs are needed before firm conclusions can be drawn. There is some evidence to suggest that melatonin is effective in treating delayed sleep phase syndrome with short-term use. There is evidence to suggest that melatonin is safe with short-term use (3 months or less).
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Disclaimer: The authors of this article are responsible for its contents, including any clinical or treatment recommendations. No statement in this article should be construed as an official position of the Agency for Healthcare Research and Quality, the National Center for Complementary and Alternative Medicine or the U.S. Department of Health and Human Services.
None of the authors have any conflicts of interest to declare.
This article is based on research conducted by the University of Alberta Evidence-based Practice Center under contract to the Agency for Healthcare Research and Quality (Contract No. 290-02-0023), Rockville, Md and support from the National Center for Complementary and Alternative Medicine, National Institute for Health, Bethesda, Md.
Financial support: This study was conducted under contract to the Agency for Healthcare Research and Quality (Contract No. 290-02-0023), Rockville, Md and support from the National Center for Complementary and Alternative Medicine, National Institute for Health, Bethesda, Md.
Authors’ contributions: N.B. planned, oversaw and participated in all steps of the systematic review process and in writing and editing the manuscript.
B.V. performed all statistical analyses and participated in writing and editing the manuscript.
N.H. participated in most steps of the systematic review process and in writing and editing the manuscript.
R.P. participated in all steps of the systematic review process and reviewed the manuscript.
L.T. conducted the literature search, provided technological expertise for the inclusion process, and participated in editing the manuscript.
L.H. participated in writing the proposal, provided methodological expertise, and participated in writing and editing the manuscript.
G.B. participated in writing the proposal, provided content expertise and participated in editing the manuscript.
T.K. participated in writing the proposal, provided methodological expertise and provided feedback on the manuscript.
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Buscemi, N., Vandermeer, B., Hooton, N. et al. The efficacy and safety of exogenous melatonin for primary sleep disorders a meta-analysis. J GEN INTERN MED 20, 1151–1158 (2005). https://doi.org/10.1111/j.1525-1497.2005.0243.x