Melatonin is a hormone produced by the pineal gland of the brain and is important for the regulation of the circadian rhythm. Millions of people take Melatonin supplements to help them sleep. Melatonin also used in the treatment of circadian rhythm disturbances such as jet-lag and shift work sleep disorders. Many older adults use melatonin as a sleep aid because of a wide spread belief that Melatonin levels drop as we get older. A study in 2000 showed that this was untrue. A recent study which analyzed the melatonin receptor sites in the brains of young and old mice at the University of Massachusetts revealed that instead of a decreasing level of Melatonin, a lack of responsiveness in the brain to melatonin may occur as a result of ageing.
Neurobiol aging 2008; Mar 29 (3)