Identification of 5-Hydroxytryptophol as a Serotonin Metabolite In Man.

Abstract
Summary 5-Hydroxytryptophol has been isolated, identified, and measured in urine of subjects with carcinoid tumors. In the urine of normal subjects and of patients with carcinoid tumors who ingested 5-HT-C14, 2.3% of the excreted C14 was attributable to 5-HTOH and its conjugates and 82.3% to 5-HIAA. These data show that 5-HTOH is a 5-HT metabolite in man as well as in animals.