The sale of melatonin is a two billion dollar a year business which must mean that a lot of people have trouble sleeping.
Sleep is an intricately choreographed neurologic process. Critical to good sleep is the circadian variation of the reticular activating system. Melatonin produced in our brains has a mild modulating effect on our sleep cycle. However, people who have had their pineal gland (a major source of melatonin) removed are able to sleep just fine.
Because melatonin sales are not regulated by the FDA, scientists decided to do controlled studies to determine its potential benefit. Multiple studies comparing melatonin to placebo found the same results. Sleep latency (the time required to fall asleep) was decreased by 7 minutes and total sleep duration was increased by 8 minutes. So, there is a measurable benefit, albeit very modest.
The flip side of the coin is safety. Accidental or purposeful overdoses with melatonin occur in one out of 20 ER visits for overdose. Some children have died or
required ventilator support to recover. The other issue is content of the product. Chemical assays of melatonin products have shown that the actual content can vary from 83% lower to 478% higher than what was claimed on the label. One chewable tablet for children contained 9 mg rather than the 1.5 mg noted on the label. Moreover, a quarter of the products sampled contained serotonin (not on the label) in addition to melatonin.
Twenty-five years ago, the science journal “Cell” cautioned about melatonin madness. They advised ignoring the hyperbole and histrionics of advertising and instead to focus on sound science.