5-HTP (5HTP) 100 mg 120 caps from Source Naturals5 HTP L 5 hydroxytryptophan Supports Normal Sleep Cycles 5 HTP (L 5 Hydroxytryptophan) is an intermediate in the natural conversion of the essential amino acid, tryptophan, to serotonin. Clinical studies have shown that 5 HTP increases the amount and availability of serotonin produced by the body. Increased brain serotonin levels may produce positive effects on emotional well being, appetite regulation, melatonin production and maintaining a healthy