Product Name: Melatonin Molecular Formula: C13H16N2O2 Molecular Weight: 232.28 Appearance: white to off-white powder Purity: 99% CAS Number: 73-31-4 EINECS number: 200-797-7 Supplier: ZhenYiBio Melatonin is a hormone produced by the pineal gland (small glands in the brain).It helps to control the cycle of your sleep and wake.Trace elements found in foods such as meat, cereals, fruits and vegetables are very abundant. Your body has its own internal clock which controls your natural sleep and wake-up times.In part,your body clock controls the amount of melatonin in your body.Usually,it starts to rise from noon to early evening, maintains a high level throughout the night, and then falls in the early morning.The lights affect the amount of melatonin produced in your body.In the short period of winter,your body may produce it earlier or later than usual. This changes may cause symptoms of seasonal affective disorder (SAD) or winter depression.