Pure psilocybin has a comparatively low level of toxicity when compared to other commonly used drugs. The amount of toxicity was discovered by studies on rats to be even lower than that of caffeine. Psilocybin overdoses on their own are likewise incredibly uncommon. Only two overdoses that were exclusively brought on by psilocybin mushrooms existed as of 2011.

: The an an an an a (TI). This assesses a substance’s relative safety in relation to the dosage necessary to achieve therapeutic benefits. Higher numbers suggest a higher safety profile for the drug. The therapeutic index of psilocybin is 641.