For Occasional Sleeplessness. Melatonin is a neurohormone produced in humans by the pineal gland. A favorite of travelers it governs the body's circadian rhythms helping the body ease into restful sleep. Melatonin is also a potent antioxidant. Source Naturals Timed Release Melatonin is formulated to allow for a gradual release of the active ingredient during an approximate six hour period. This provides the body with a more even absorption of melatonin.