6-Hydroxy-5-methoxy-N,N-dimethyltryptamine and 5-methoxy-N,N- dimethyltryptamine were synthesized and their psychotropic effects compared on trained rats in a Skinner box. The nonhydroxylated form was the more potent. The metabolism of 5-methoxytryptophol acetate ester was also studied to determine whether hydroxylation might occur in other than the six position with exogenous indoles. One metabolite was formed, with properties of a hydroxy-5- methoxyindole-3-acetic acid, which proved on chromatography not to be the 6-hydroxy structural isomer. Pharmacologic and metabolic studies suggest that psychotropic activity of tryptamines may result from metabolites other than the 6-hydroxylated forms.