Melatonin: A low-moderate report by the Agency for Healthcare Research and Quality found that melatonin decreased sleep onset latency and increased sleep efficiency in normal sleepers. The University of Maryland Medical Center Alternative Medicine Guide also suggests some studies point to melatonin for help with disrupted circadian rhythms (such as people with jet lag or working night shifts) and those with low melatonin levels to sleep better. A few clinical studies suggest melatonin can help reduce the time it takes to fall asleep and boost daytime alertness. Buscemi N, et al. "Melatonin for Treatment of Sleep Disorders." US Department of Health & Human Services.