Small doses of melatonin shift your sleep cycle. In the morning if you want to delay your cycle, and in the evening if you want to advance it. People use large

Small doses of melatonin shift your sleep cycle. In the morning if you want to delay your cycle, and in the evening if you want to advance it. People use larger doses of melatonin as a hypnotic to make them fall asleep right away, but that's not the only use.