Melatonin Notes
USE AS MEDICATION
The hormone melatonin is used to treat circadian rhythm sleep disorders and some types of insomnia.
Studies have found that the use of melatonin can help entrain the circadian clock to environmental cycles and have beneficial effects for the treatment of certain forms of insomnia (2004).[105] Prolonged release melatonin has shown good results in treating insomnia in older adults (2007).[106]
A 2004 review found that melatonin significantly increased total sleep time in people suffering from sleep restriction.[17]
Other studies have found that for certain types of sleep disorders, melatonin is not effective. A 2006 review found that although it is safe for short term use (of three months or less), there is "no evidence that melatonin is effective in treating secondary sleep disorders or sleep disorders accompanying sleep restriction, such asjet lag and shiftwork disorder."[58]
In a 2005 study, researchers concluded that while "there is some evidence to suggest that melatonin is effective in treating delayed sleep phase syndrome, ...there is evidence to suggest that melatonin is not effective in treating most primary sleep disorders with short-term use (4 weeks or less)."[59]
[edit]Dosage
Melatonin tablets/capsules often contain three to ten times the amount needed to produce physiologic nocturnal blood melatonin levels for a more rapid sleep onset. Studies suggest that smaller doses (for example 0.3 mg as opposed to 3 mg) are just as effective.[61]
Large doses of melatonin can even be counterproductive: Lewy et al.[107] provide support to the "idea that too much melatonin may spill over onto the wrong zone of the melatonin phase-response curve" (PRC). In one of their blind subjects, 0.5 mg of melatonin was effective while 20 mg was not. Solomon Labs tested initial doses of 30 and 60 milligrams and found very little efficacy even at those levels.[107][108]
