Psilocybin is a naturally occurring psychedelic

Psychedelic drug

A psychedelic substance is a psychoactive drug whose primary action is to alter cognition and perception. Psychedelics are part of a wider class of psychoactive drugs known as hallucinogens, a class that also includes related substances such as dissociatives and deliriants...

 prodrug

Prodrug

A prodrug is a pharmacological substance administered in an inactive form. Once administered, the prodrug is metabolised in vivo into an active metabolite, a process termed bioactivation. The rationale behind the use of a prodrug is generally for absorption, distribution, metabolism, and...

, with mind-altering effects similar to those of LSD

LSD

Lysergic acid diethylamide, abbreviated LSD or LSD-25, also known as lysergide and colloquially as acid, is a semisynthetic psychedelic drug of the ergoline family, well known for its psychological effects which can include altered thinking processes, closed and open eye visuals, synaesthesia, an...

 and mescaline

Mescaline

Mescaline or 3,4,5-trimethoxyphenethylamine is a naturally occurring psychedelic alkaloid of the phenethylamine class used mainly as an entheogen....

, after it is converted to psilocin

Psilocin

Psilocin , an aromatic compound, sometimes also spelled psilocine, psilocyn, or psilotsin, is a psychedelic mushroom alkaloid. It is found in most psychedelic mushrooms together with its phosphorylated counterpart psilocybin...

. The effects can include altered thinking processes, perceptual distortions, an altered sense of time, and spiritual experiences, as well as adverse reactions such as nausea

Nausea

Nausea , is a sensation of unease and discomfort in the upper stomach with an involuntary urge to vomit. It often, but not always, precedes vomiting...

 and panic attack

Panic attack

Panic attacks are periods of intense fear or apprehension that are of sudden onset and of relatively brief duration. Panic attacks usually begin abruptly, reach a peak within 10 minutes, and subside over the next several hours...

s. Psilocybin is produced by over 200 species of mushroom

Mushroom

A mushroom is the fleshy, spore-bearing fruiting body of a fungus, typically produced above ground on soil or on its food source. The standard for the name "mushroom" is the cultivated white button mushroom, Agaricus bisporus; hence the word "mushroom" is most often applied to those fungi that...

s, collectively known as psilocybin mushrooms. The most potent are members of the genus Psilocybe

Psilocybe

Psilocybe is a genus of small mushrooms growing worldwide. This genus is best known for its species with psychedelic or hallucinogenic properties, widely known as "magic mushrooms", though the majority of species do not contain hallucinogenic compounds...

, such as P. cubensis

Psilocybe cubensis

Psilocybe cubensis is a species of psychedelic mushroom whose principal active compounds are psilocybin and psilocin. Commonly called Boomers, Cubes or Gold Caps, it belongs to the Strophariaceae family of fungi and was previously known as Stropharia cubensis.-Taxonomy and naming:The species was...

, P. semilanceata

Psilocybe semilanceata

Psilocybe semilanceata, commonly known as the liberty cap, is a psychedelic mushroom that contains the psychoactive compounds psilocybin and baeocystin. Of the world's psychoactive mushrooms, it is the most common in nature, and one of the most potent...

, and P. cyanescens

Psilocybe cyanescens

Psilocybe cyanescens is a species of potent psychedelic mushroom. The main compounds responsible for its psychedelic effects are psilocybin and psilocin. It belongs to the family Strophariaceae...

, but psilocybin has also been isolated from about a dozen other genera

Genera

Genera is a commercial operating system and development environment for Lisp machines developed by Symbolics. It is essentially a fork of an earlier operating system originating on the MIT AI Lab's Lisp machines which Symbolics had used in common with LMI and Texas Instruments...

.

In Mexico, Central America, and South America, psilocybin-containing mushrooms have been ingested for thousands of years in spiritual ceremonies.