Pure Encapsulations 5-HTP 100mg 60 Capsules5 HTP 100mg 5 Hydroxytryptophan Promotes healthy mood balance 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 group (OH) to tryptophan, forming the 5 HTP intermediate. In the body, 5 HTP is converted to serotonin with the removal of a carboxyl group (COOH) by a second enzyme. 5 HTP is involved in the regulation of endocrine