Melatonin releases from the pineal gland, reaching its peak at night to help maintain healthy cell health throughout the body. Secretion of melatonin declines significantly with age, as the pineal gland becomes calcified. Jet lag, shift work, and poor vision can disrupt melatonin cycles.

Melatonin keeps our circadian cycle in tune. Not only does this hormone work to maintain cell health, it appears to regulate a system of self-repair and regeneration. As melatonin diminishes with age, our biological functions are impaired. Melatonin also has strong antioxidant properties. It directly scavenges both hydroxyl and peroxyl free radicals, and it does so more effectively than most other antioxidants. It also greatly potentiates the efficiency of other endogenous and exogenous antioxidants. Melatonin is especially important for protecting cellular DNA against peroxynitrite damage by inhibiting peroxynitrite free radical reactions. Some research has found that melatonin increases the speed of falling asleep and adds to the quality of sleep in about 60% of people who use it.