The aim of this study was to investigate the influence of melatonin on metabolism and the implementation of the sleep-wake cycle. Methodology. Publications for this review were collected from PubMed, MedLine, and Google Scholar databases. Results. Melatonin is the main hormone that communicates the main circadian clock, located in the suprachiasmatic nucleus of the hypothalamus, and the peripheral biological clock located in brain cells and other organs. Melatonin production is related to day and night cycles, with peak production of the hormone occurring at night. Considering the pathophysiological mechanisms triggered by melatonin deficiency, the question reasonably arises about the possibilities of treating metabolic disorders (including type 2 diabetes), cardiovascular pathology and sleep disorders with melatonin preparations. Domestic and foreign publications provide reports of the clinically successful use of such drugs to improve sleep quality, increase sensitivity to glucose, lower blood pressure, reduce myocardial ischemia, and improve anthropometric parameters. All this makes melatonin a promising drug for managing cardiovascular risks against the background of metabolic disorders.