P.cubensis is one of a number of closely-related psychoactive species, though it is the most well-known (there are also other psychoactive mushrooms that are not closely related to P. cubensis and have somewhat different effects). The substances responsible for the psychoactive effects are psilocybin, psilocin, baeocystin, and norbaeocystin. The concentration of these substances can vary significantly from one individual mushroom to another.