Is melatonin really an effective treatment of insomnia?
Yes, but only if melatonin levels are low. Melatonin plays an important role in the induction of sleep. Several double-blind trials have shown melatonin supplementation to be very effective in promoting sleep and relieving insomnia.4-8 However, the sleep-promoting effects of melatonin are most apparent when melatonin levels are low.9 In other words, melatonin is not like taking a sleeping pill. It will only produce its effects in individuals with a melatonin deficiency. When melatonin is given just before going to bed to healthy subjects or to patients with insomnia who have normal melatonin levels, it produces no sedative effect. That is because, normally, just prior to going to bed, there is a rise in melatonin secretion. Melatonin supplementation is only effective as a sedative when the pineal gland’s own production of melatonin is very low. However, low melatonin levels are thought to be an extremely common cause of insomnia in the elderly.10 In one of the most interesting studies,
