Certain species of mushrooms contain a naturally occurring psychedelic compound known as psilocybin. It has been used for centuries by indigenous cultures in religious and healing rituals. In recent years, psilocybin has gained increasing attention as a potential treatment for various mental health conditions, such as depression, anxiety, and addiction. But what does psilocybin do to the brain? When psilocybin is ingested, it is converted into psilocin, which is the active compound responsible for its psychoactive effects.