THE BIG SLEEP Clean Melatonin 36 Pack. Benefits: Regulate the sleep-wake cycle. Promote a deeper, more relaxed sleep. Reset your internal clock and ease jetlag. Key Ingredients: Melatonin is a hormone that helps regulate sleep and wake cycles, also known as circadian rhythms. It's produced in the pineal gland of the brain in response to darkness. Melatonin levels increase at night and decrease during the day. Disruptions to light exposure, like jet lag or shift work, can disrupt melatonin production.. :