Exogenous melatonin is not effective in the management of secondary sleep disorders or sleep disorders accompanying sleep restriction, such as jet lag or shiftwork disorder. In a meta-analysis by Buscemi and colleagues (p 385), six randomised controlled trials showed no evidence that melatonin had an effect on sleep onset latency in people with secondary sleep disorders and nine trials showed no effect on onset in people who had sleep disorders accompanying sleep restriction. There is evidence, however, that melatonin is safe with short term use.
Figure 1.
Credit: FREDRIK SKOLD/PHOTOGRAPHER'S CHOICE/GETTY