Can melatonin extend life?
No studies of humans support this notion. In one group of animal studies, the pineal glands of young mice were transplanted into old mice, and vice versa. The old mice allegedly lived longer. The young mice allegedly died sooner. Some strains of mice used in these studies, however, have a genetic defect that keeps them from producing melatonin. The alleged benefits therefore could not have come from melatonin.