Tolerance to Hallucinogenics
Users quickly develop a high degree of tolerance to the effects of classic hallucinogenics, such that repeated use requires increasingly larger doses to produce similar effects. Unlike most other hallucinogens, DMT does not appear to induce tolerance.
Use of classic hallucinogenic drugs also produces tolerance to other drugs in this class, although not to drugs that do not act directly on the same brain cell receptors. In other words, there is no cross-tolerance to drugs that act on other neurotransmitter systems, such as marijuana, amphetamines, or PCP, among others.
Tolerance for hallucinogenic drugs is short-lived—it is lost if the user stops taking the drugs for several days—and physical withdrawal symptoms are not typically experienced when chronic use is stopped.