Melatonin is produced by the pineal gland, a pea-sized gland at the base of the brain. Although the exact functions of melatonin are still under study, it is involved in the synchronization of hormone secretion. This natural daily cycle of hormone release in the body is commonly referred to as circadian rhythm. The human body is under the influence of an internal clock which controls the secretion of various hormones at different times of the day in order for the body to function properly. The secretion of melatonin is triggered by the dark and is suppressed by natural daylight, thereby controlling periods of sleepiness and wakefulness. However, melatonin is more than a sleeping pill. It can also be beneficial in maintaining the immune system. It works in concert with vitamin B6 and zinc to reverse the decline of the immune system that comes with aging. In addition, melatonin has strong antioxidant activity and, as such, supports the hormonal and metabolic networks in the body. These networks undergo additional changes due to intense physical exercise, mental and emotional stress, or even poor nutrition. Some evidence suggests that melatonin may, in fact, lighten and enhance one's mood considerably. Melatonin is also reported to be beneficial in dealing with premenstrual syndrome. Ultimate Nutrition's Melatonin is especially designed and manufactured for performance athletes who may need nature's helping hand to get their rest and for travelers to better control their sleep cycle. A key benefit of melatonin is its ability to restore the bodys natural hormonal and metabolic balance for overall health.