Melatonin does not become black when eaten: 1, melatonin is an amine hormone secreted by the human pineal gland, which exists in the normal human body, it is a substance that can make the skin pigment lighter, under normal circumstances, 2-3 o’clock at night is the peak of melatonin secretion, when the day or light becomes brighter, melatonin will reduce secretion or stop secretion. 2, its main role is not to make the human skin It is used to regulate circadian rhythms as well as to slow down aging. This hormone can shorten the time to fall asleep, improve the quality of sleep, make the deep sleep stage longer, so that the number of awakenings during sleep is reduced, especially for patients with sleep disorder it can regulate the circadian rhythm, so that their sleep to return to a normal state, night sleep and day awakening.