PURE ENCAPSULATIONS - 5-HTP 100 mg (5-Hydroxytryptophan) - 60 veggie Capsule(s) - NPN: 80016104 -- Features plant-derived 5-HTPUsed as a sleep aid5-Hydroxytryptophan (5-HTP) is an intermediate in the natural synthesis of serotonin from the essential amino acid tryptophan. The enzyme tryptophanhydroxylase adds a hydroxyl group (OH) to tryptophan, for