Description Melatonin is a metabolic hormone made in the pineal gland, retina, and intestines. Melatonin is released into the blood stream by the pineal gland (which resides in the brain) to set your bodies biological clock and initiate sleep. Darkness stimulates the pineal gland and causes it to produce more melatonin. Day light stops your bodys production of melatonin. Melatonin helps to promote healthy sleep patterns. Melatonin also protects cells from free radical damage, and directs the release of growth and sex hormones. Vitamin B6 plays an important role in brain chemistry and nervous system function.