N,N-Dimethyltryptamine or DMT is a naturally occurring psychedelic drug related to the psilocybins. It is usually derived from a vine that grows in the Amazon rain forest. It has been used by Amerindians since ancient times for its psychedelic effects.
It was artificially synthesized in 1931 and has been commonly used as a recreational drug. It was only after DMT was artificially synthesized that it was recognized as the active ingredient in ayahuasca, a potion made from the vine. It is effective at very low doses (about 30mg for a 75kg individual). It works by binding to certain seratonin and dopamine receptors.