DMT: dosage

Intravenous studies found hallucinogenic effects starting at 0.2 mg/kg and above [1]. At 0.2 and 0.4 mg/kg, effects included a rapidly moving, brightly colored visual display [2]. Lower IV doses, 0.1 and 0.05 mg/kg, produced mainly affective and body-centered (somaesthetic) effects [2]. Oddly, the 0.1 mg/kg dose was rated as producing the least desirable effects of the doses tested [2] — lower is not automatically gentler or more pleasant.

Timing with IV DMT is fast and short. Psychological effects begin almost immediately, peak at 90 to 120 seconds, and are almost completely resolved by 30 minutes [2]. Peak subjective effects land within 2 minutes and are negligible by the half-hour mark [1]. Blood pressure, heart rate, pupil size, and rectal temperature all rise with dose [1].

In oral ayahuasca, preparations delivering 0.6 to 0.85 mg of DMT per kg of body weight produced significant subjective effects [3], peaking much later — between 1.5 and 2 hours after dosing [3]. At the higher of those doses, diastolic blood pressure rose by 9 mm Hg at 75 minutes [3]. DMT alone is reported to be inactive by mouth, producing effects only when injected, sniffed, or smoked [4], but oral ayahuasca preparations containing DMT do produce measurable effects [3].

The IV dosing data comes from studies involving people experienced with hallucinogens [1]. That prior experience is not the same as dosing alone with an unknown quantity. None of the sources on this page give dose-response data for smoked or vaporized DMT.

References

1. Dose-response study of N,N-dimethyltryptamine in humans. I. Neuroendocrine, autonomic, and cardiovascular effects — Archives of General Psychiatry (JAMA Network)
2. Dose-response study of N,N-dimethyltryptamine in humans. II. Subjective effects and preliminary results of a new rating scale — Archives of General Psychiatry (JAMA Network)
3. Human pharmacology of ayahuasca: subjective and cardiovascular effects, monoamine metabolite excretion, and pharmacokinetics — Journal of Pharmacology and Experimental Therapeutics (ASPET)
4. DMT — Encyclopaedia Britannica