Melatonin has multiorgan effects.

Melatonin, widely used to counter transatlantic travel jet lag and insomnia, is synthesized in the suprachiasmatic nucleus of the anterior pituitary gland. Its release into the circulation is stimulated by the onset of darkness, followed by a progressive decrease in blood levels with the onset of dawn. Melatonin administration can maintain the quality of sleep and help to counteract age-induced cognitive decline. Melatonin can also limit the severity of a variety of cardiovascular and cerebrovascular diseases, diabetes, and cancer.