Objective

Melatonin plays an important role in metabolic regulation and has been suggested to influence adipose tissue function through the modulation of leptin and adiponectin. However, evidence from randomized controlled trials (RCTs) on the effects of melatonin supplementation on these adipokines is inconsistent.
Methods
In this systematic review and meta-analysis, we searched PubMed, Web of Science, Scopus, and Google Scholar for RCTs on this topic published up to July 2025. We calculated weighted mean differences (WMDs) using random-effects models to identify net changes in risk factors.
Results
Our search yielded nine RCTs (with 11 arms). We found that melatonin supplementation had no significant effects on serum leptin (WMD, 0.172 ng/mL; 95% confidence interval [CI], −2.15 to 2.50; n=11) or adiponectin (WMD, 1.432 µg/mL; 95% CI, −0.112 to 2.976; n=7) levels.
Conclusion
This meta-analysis showed that melatonin supplementation does not significantly affect serum leptin and adiponectin levels. However, further studies are needed to confirm this.