psilocybine

Psilocybin, sometimes rendered as psilocybine in some languages, is a naturally occurring psychedelic compound found in several species of agaric mushrooms, notably in the genus Psilocybe. It is a phosphorylated prodrug of psilocin (4-hydroxy-N,N-dimethyltryptamine), the compound responsible for the psychoactive effects.

After ingestion, enzymes dephosphorylate psilocybin to psilocin, which then acts as a serotonin receptor agonist, with high affinity for 5-HT2A receptors. This activity is thought to underlie most perceptual and cognitive effects. The onset of effects is typically 20–60 minutes after oral intake, with peak effects at 2–3 hours and a total duration of about 4–6 hours. The subjective experience varies with dose, setting, and individual susceptibility, and can include visual alterations, changes in mood and thought, and experiences described as mystical or transcendental. Physiological effects may include pupil dilation, tachycardia, increased blood pressure, dizziness, nausea, and, less commonly, anxiety or paranoia.

Chemically, psilocybin is one of several tryptamine hallucinogens and is usually consumed by eating or brewing the mushrooms. It is also possible to synthesize psilocybin in the laboratory. Psilocin is rapidly dephosphorylated and eliminated; total clearance occurs within a day or two.

Legal status varies by country. In many places psilocybin is controlled or illegal, though recent years have seen reform in several jurisdictions and renewed interest in medical research under controlled conditions. Clinical studies, particularly since the 2000s, have explored psilocybin-assisted therapy for treatment-resistant depression, anxiety associated with life-threatening illness, and other mood disorders; results are promising but preliminary, and research continues under regulatory oversight.