Psilocybin (also known as psilocybine), is a psychedelic alkaloid of the tryptamine family.
It is present in many species of fungi, including those of the genus Psilocybe, such as Psilocybe cubensis and Psilocybe semilanceata, but also reportedly isolated from a dozen or so other genera.
Psilocybin-containing mushrooms are commonly called magic mushrooms, or simply "shrooms".
Effects of psilocybin are comparable to LSD, but last for a shorter time, although intensity and duration vary depending on dosage, individual physiology, and set and setting.
Psilocybin and psilocin are listed as Schedule I drugs under the United Nations 1971 Convention on Psychotropic Substances.
Schedule I drugs are illicit drugs that are claimed to have no known therapeutic benefit.