NATURAL OR SYNTHETIC? Since researchers isolated the hormone melatonin, it has become available in tablet form as a food supplement that aids in sleep problems. Two grades are available -- natural and synthetic. Natural melatonin, made from the extracts of the pineal glands of animals, usually sheep, is not necessarily of a better quality. It could contain impurities such as those that caused tryptophan supplements to be taken off the market several years ago. Synthetic grade melatonin is manufactured under laboratory control. Measurements are exact so if the tablets are supposed to contain 3 mg. of melatonin, you can be sure that is what they contain. Synthetic melatonin is identical to the melatonin produced by the pineal gland. We recommend these websites to purchase pharmaceutical grade 100% synthetic Melatonin: www.biovea.co.uk www.agestop.co.uk