Melatonin is indeed a hormone that is produced by the pineal gland in the brain, mostly during the night with its secretion being impaired by exposure to bright light. It has appropriately been termed the “Dracula hormone” and seems to be related to the circadian (from “circa” around and “dian” day) cycle of our body. It has been shown to be of benefit in “jet lag,” a condition that induces drowsiness, irregular sleeping rhythms and moodiness in people changing time zones or working shift hours. But the dosage required and the appropriate regimen for taking melatonin pills is unclear.
Studies have also shown that melatonin can induce drowsiness with as little as 0.3 mg being effective. The liquid version in which the melatonin is dissolved in a solvent seems to work better than the pill form.
All of this sounds like the activity of a drug, so how is it that melatonin is readily available without a prescription? The reason is that both in Canada and the U.S., it qualifies as a dietary supplement since it occurs naturally in a number of foods. This was first discovered in a trial using tart cherry juice for arthritic pain with subjects reporting they felt drowsy. A subsequent chemical analysis of the juice revealed the presence of melatonin. It is also found in flaxseeds, walnuts, yellow bell peppers and almonds, but goji berries contain the most melatonin, albeit far less than the amount available in supplements. While melatonin in foods is not likely to produce a significant effect for insomniacs, its presence in food allows melatonin to be marketed as a dietary supplement.
