Melatonin supplementation and anthropometric indicators of obesity: A systematic review and meta-analysis

Nutrition. 2021 Nov-Dec:91-92:111399. doi: 10.1016/j.nut.2021.111399. Epub 2021 Jun 24.


Objective: According to in vivo and in vitro studies, melatonin appears to be a potential supplement for obesity reduction. The aim of this study was to review the literature on randomized clinical trials that evaluated the effects of melatonin supplementation on anthropometric indicators of obesity in humans.

Methods: We conducted a systematic review with meta-analysis in the following databases: Pubmed, LILACS, Scielo, Scopus, Web of Science, Cochrane, and Embase. We included studies that evaluated melatonin supplementation's effects, compared with placebo, on anthropometric measures, including body weight, body mass index (BMI), and waist circumference, in people ≥18 y of age. This systematic review and meta-analysis were registered on PROSPERO: CRD42021241079.

Results: Of the 23 studies included, 11 showed significant results from melatonin supplementation on weight loss, BMI, or waist circumference, compared with placebo. In the meta-analysis, melatonin supplementation significantly reduced body weight (standardized mean difference, -0.48; 95% confidence interval, -0.94 to -0.02; P = <0.01; I2 = 92%). Results for BMI and waist circumference were null. The I2 tests were significant for the analyses with significant results.

Conclusion: The results demonstrated that melatonin supplementation was responsible for significantly reducing body weight. More studies are needed before melatonin can be recommended for weight loss.

Keywords: BMI; Melatonin; Obesity; Waist circumference; Weight loss.

Publication types

  • Meta-Analysis
  • Review
  • Systematic Review

MeSH terms

  • Body Mass Index
  • Body Weight
  • Dietary Supplements
  • Humans
  • Melatonin*
  • Obesity / drug therapy
  • Randomized Controlled Trials as Topic
  • Waist Circumference


  • Melatonin