Melatonin is a potent free radical scavenger naturally produced in the pineal gland and present in high amounts in the gastrointestinal tract.* It is involved in many of the body, brain and glandular biological functions including regulation of normal sleep/wake cycles, regulation of the immune system and maintenance of a healthy gastrointestinal lining.* NOW Melatonin Sustained Release Tablets allow for steady release and more gradual, sustained utilization. This sustained release tablet is formulated to release over a 4-hour period. Natural color variation may occur in this product.