DMT (N,N-dimethyltryptamine) is an indolealkylamine with high affinity at serotonin 5-HT₂A receptors. It is the principal psychoactive constituent of ayahuasca, where it is rendered orally active by harmala alkaloids (MAO-A inhibitors) from Banisteriopsis caapi. Smoked, vaporized, or injected DMT bypasses MAO and produces a rapid, short experience (typically 5–20 minutes for smoked, 15–30 minutes for IM).
5-MeO-DMT (5-methoxy-N,N-dimethyltryptamine) is a related tryptamine with markedly different pharmacology: it has high affinity at 5-HT₁A as well as 5-HT₂A, and the subjective experience is described differently — typically less visual, more ego-dissolving. It is found in the secretion of Incilius alvarius (Sonoran Desert toad) and in several plant species, and is also synthesized.
Both compounds are metabolized rapidly. Plasma half-life of DMT is roughly 10–15 minutes; 5-MeO-DMT is similar. Neither substance is associated with classical physical dependence, but both can cause cardiovascular and psychological adverse events, especially in uncontrolled settings.