Patients are happy with melatonin supplements but scientist raise doubts about the effect of these supplements. This is a hormone which helps to regulate sleep cycles and circadian timing. This is produced naturally by the body at night. When taken as supplements during the day it works but clinical trails says that it is not very effective in the night.

There is no clear cut evidence that melatonin has the same sleep-inducing effect in the night. The study was conducted by researchers at Brigham and Women's Hospital and Harvard Medical School. This study was published in the current issue of the journal Sleep. It had 36 volunteers each was housed in a soundproof room with dim lighting, no windows and no hint of real time.

The study extended for a period of four-weeks and the volunteers were kept on strict 20-hour cycles of sleep and wakefulness. This was done mainly to break the body's 24-hour clock. The study's lead author, James Wyatt, says that this would mimic the off-hour sleep-wake cycle that shift workers and jet-lagged travelers often struggle with. In the night the participants were given either melatonin or a placebo.