5-HTP (5-hydroxytryptophan)Promotes a healthy balance of moods Includes plant derived 5 hydroxytryptophan Promotes sleep 5 Hydroxytryptophan (5 HTP) is an intermediate in the natural synthesis of serotonin from the essential amino acid tryptophan. The enzyme tryptophan hydroxylase adds a hydroxyl (OH) group to tryptophan, forming the intermediate 5 HTP. In the body, 5 HTP is converted to serotonin by the removal of a carboxyl group (COOH) by another enzyme. 5 HTP is involved in