Dimethyltryptamine (DMT) is a psychedelic tryptamine, similar in structure to the neurotransmitter serotonin.
DMT is a powerful psychoactive substance. If DMT is smoked, injected, or orally ingested with an MAOI, it can produce powerful entheogenic experiences including true hallucinations (perceived extensions of reality). A trip sitter is often employed to assist the drug user in staying physically and mentally healthy, and, in the case of smoked DMT, to catch the pipe when the user loses awareness of it.
If DMT is smoked, the maximal effects last for a short period of time (5 - 30 minutes +). The onset after inhalation is very fast (less than 45 seconds) and maximal effects are reached within about a minute.
If DMT is insufflated (snorted through the nostrils) it will last slightly longer than if smoked and has less powerful effects.
Injected DMT produces an experience similar to inhalation in duration, intensity, and characteristics, although by some accounts it is more emotionally clinical (versus spiritual).
Writers on DMT include Terence McKenna and Jeremy Narby, though most scientists who study psychedelic drugs treat their writings with skepticism. McKenna writes of his experiences with DMT in which he encounters entities he describes as "Self-Transforming Machine Elves". McKenna believed DMT to be a tool that could be used to enhance communication and allow for communication with other-worldly entities. Other users report visitation from external intelligences attempting to impart information. These Machine Elf experiences are said to be shared by many DMT users.