Melatonin is a hormone naturally produced in the body that is involved in our natural sleep cycle. Melatonin is important for the maintenance of circadian rhythm and our sleep-wake cycle. Melatonin amounts may vary depending on the person. Traveling to different time zones, nightshift work, lifestyle habits and artificial light or light-emitting electronics, like TV or mobile phones, can disrupt the normal sleep-wake cycle. Time-release melatonin is designed to help mimic the bodys natural pattern of melatonin release throughout the night.