The metabolism of DMT in the whole rat brain homogenate is reported. Studies were conducted using tritiated DMT and DMT-N-Oxide, and metabolites were identified and quantified using TLC and liquid scintillation counting techniques. Metabolite confirmation was obtained by incubation of deuterated DMT followed by GC-MS. The metabolites of DMT were identified as indol-acetic-acid, N-methyl-tryptamine, 2-MTHBC, tryptamine, tetra-hydro-beta-carboline. Mechanisms for the formation of beta-carbolines from DMT are discussed. A cyclic pathway for the synthesis and metabolism of DMT in brain tissue is proposed.