Psilocybin is not considered to be addictive nor does it cause compulsive use. One reason is that the intense experience, which can be physically and mentally challenging, may cause people using psilocybin to limit their frequency of use.

Another reason is that the human body quickly builds tolerance to psilocybin, such that people require much higher doses after only a few days of repeated use, making it extremely difficult to have any effect after more than four days of repeated usage.

And because of the similar brain receptors involved in their effects, cross-tolerance occurs with LSD and psilocybin, which means that if someone takes LSD one day, the effects of taking psilocybin the next day will be diminished.

See the fact sheet for more information and sources.