Melatonin is the hormone of sleep in animals and humans.
It is synthesized from tryptophan, an essential amino acid. The circadian rhythm of day night cycles are regulated by melatonin levels. Human melatonin levels only become regular at three months of age, and as humans age melatonin levels decrease from the age of thirty years. In adolescents, nightly melatonin release is delayed, leading to later sleeping and waking times.
Melatonin is a powerful antioxidant and anti-inflammatory agent and may increase cytokine production.
Foods that increase melatonin include cherries, bananas, grapes, rice and cereals, some herbs, olive oil and wine in moderation.
Melatonin can also be used to help jet lag, but needs to be synchronised with light, as light will depress melatonin production.
Melatonin is used in sleep disorders, in particular secondary sleep disorders and sleep onset latency in people with a primary sleep disorder. Melatonin use seems to be variable in the effectiveness to help people with sleep disorders on an individual basis. Night workers do not seem to benefit from melatonin use.
Other benefits of melatonin are protection from radiation by scavenging of free radicals, melatonin may also help tinnitus.
Melatonin may be prescribed on an individual basis with slow release oral tablets, normal oral melatonin tablets or sublingual drops. None of the above medication should be given without medical supervision.