Our laboratory using techniques of GLC-mass spectrometry as well as administration of DMT to humans and animals has been able to provide some data regarding these criteria. DMT is present in human tissue although it is metabolized extremely quickly. Animal data indicates that unlike other hallucinogenic agents tolerance to DMT does not seem to develop. The psychological aspects of DMT administration are, however, most interesting. Unlike previous investigators we have found little in the way of visual hallucination or distortions. Subjects become internalized and at times frankly paranoid. These and other results of this ongoing project will be discussed.