Knock-out contains Melatonin, in the hormone the brain believed to maintain regular sleeping patterns. Schiff has added Valerian and Theanine herbs, long revered for their calming properties. (These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease). Bi-Layer tablet with a rapid release layer and a time release layer. No added sugar (sucrose, fructose, lactose), salt (sodium chloride), yeast wheat, gluten or milk. No preservatives, artificial colors or artificial flavors. Sleep support.