Drug-free. Melatonin 5 mg: To help you fall asleep faster, wake up less, and feel refreshed in the morning. Elderberry: A powerful antioxidant believed to support your body's own defenses. Zinc and Vitamins C, D & E: Antioxidants to support a healthy immune system. Sweet dreams lie ahead with Unisom Simple Slumbers immunity. It's completely drug-free, and works with your body's natural sleep cycle. Melatonin + our immunity blend (of elderberry, zinc and vitamins C, D & E) helps you fall asleep gently and supports your immune system while you sleep, so you can wake up refreshed.