The primary function of melatonin is regulation of day-night cycles. Human infants’ melatonin levels become regular in about the third month after birth, with the highest levels measured between midnight and 8:00 am.Human melatonin production decreases as a person ages.
Melatonin might improve sleep in autistic people. Children with autism have abnormal melatonin pathways and below-average physiological levels of melatonin. Melatonin supplementation has been shown to improve sleep duration, sleep onset latency, and night-time awakenings.