Natrol? Melatonin Liquid assists with occasional sleeplessness and helps you fall asleep faster, stay asleep longer and wake up feeling refreshed. It is great tasting and an ideal alternative to taking pills before bed.Melatonin serves as the body?s biological clock, managing the sleep and wake cycles. Age, everyday stress and diet choices induced by busy lifestyles can take a toll on the body?s production of melatonin.