Not being able to sleep in no small matter. Melatonin P.R. (prolonged release)3mg is a gentle way to help alleviate temporary issues of insomnia. It helps get you to sleep and then continually release through the night time hours to keep you asleep. In the morning you awake refreshed and ready to face the day!. A prolonged lack of sleep may indicate a deeper issue so always be sure to check with your doctor if this is your experience.