DMT is inactive orally at dosages of over 1000mg. With intramuscular injection, there is an abrupt threshold of activity shown with 30mg, and a complete psychedelic experience results from the administration of 50-70mg (75mg subcutaneously, 30mg by inhalation). An unusual feature of the induced intoxication is the speed of onset and short duration. Within 5 minutes of administration there is mydriasis [dilated pupils], tachycardia [rapid heart beat], a measurable increase in blood pressure, and related vegetative disturbances which usually persist througout the drug experience. In 10-15 minutes, the full intoxication is realized, generally characterized by hallucinations with the eyes either open or closed, and extensive movement within the visual field. There is difficulty in the expression of one's thoughts, and in concentration on a given subject. There is usually a mood change to the euphoric with unmotivated laughter, but instances have been reported in which paranoid ideation has promoted anxieties and feelings of forboding into a state of panic. The subject is largely symptom-free at 60 minutes, although some residual effects have been seen in the second hour. With the inhalation route of administration the time scale is contracted, with onset of effects noted in 10 seconds, a short period of full intoxication at 2-3 minute, and a complete freedom from any residual effects within 10 minutes. At higher drug levels, there are increased vegetative symptoms, and these effectively overwhelm the psychedelic experience at dosages of 150mg i.m. Interactions with other drugs are rarely seen; a sensitivity has been observed with pretreatment with methlysergide, but there is no cross-tolerance with LSD. Repeated usage does not appear to lead to either physical or psychological dependency.
DMT is explicitly named as a Schedule I drug in the Federal Controlled Substances Act; registry number 7435