Pure Encapsulations Melatonin-SR 60 CapsulesMelatonin SR Sustained release melatonin to promote restful slumber Melatonin SR provides sustained release MicroActive melatonin to promote healthy rest cycles. Melatonin is a hormone produced by the pineal gland, which regulates the bodys wake rest cycle. Melatonins primary role is the regulation of the bodys circadian rhythm, endocrine secretions, and rest patterns. Studies indicate that it facilitates the onset of rest as well as rest efficiency,