Melatonin is a hormone that is produced by the pineal gland in the brain. The production of melatonin is promoted by darkness, so it is produced at night once your lights are out. It synchronizes your sleep-wake cycle with night and day – and its production ceases in light (daylight or synthetic light.) In doing so it regulates the sleep-wake cycle of your circadian rhythm. Many people with insomnia take melatonin as capsules or tablets or in the liquid state in order to help them sleep and to extend the duration of sleep.  A trial carried out on the use of melatonin supplements on those suffering from Delayed Sleep-Wake Phase Disorder (DSWPD) showed that 52.8% of subjects showed more than minimal improvement over those taking a placebo. It should be noted that those carrying out this trial have been found to have a conflict of interests regarding its results. Doctors say that melatonin supplements are of limited use for adults and children. The Academy of Sleep Medicine (AASM) has concluded that scientific support is insufficient for the use of melatonin in reducing insomnia and improving the quality of sleep of insomniacs.