A naturally occurring psychedelic compound found in certain mushrooms that produces altered states of consciousness.
Psilocybin (4-phosphoryloxy-N,N-dimethyltryptamine) is a naturally occurring psychedelic prodrug compound produced by more than 200 species of fungi, most notably those in the genus Psilocybe. It belongs to the tryptamine class of compounds and is structurally similar to the neurotransmitter serotonin.
Psilocybin has the molecular formula C₁₂H₁₇N₂O₄P. Its structure consists of a tryptamine backbone with a phosphate group attached at the 4-position of the indole ring. This phosphate group makes psilocybin water-soluble and more stable than its active metabolite, psilocin.
Psilocybin itself is not psychoactive. When ingested, it is rapidly dephosphorylated by alkaline phosphatase enzymes in the body, converting it to psilocin (4-hydroxy-N,N-dimethyltryptamine). This conversion primarily occurs in the acidic environment of the stomach and in the liver. Psilocin is the compound that actually crosses the blood-brain barrier and produces psychedelic effects by binding to serotonin receptors, particularly the 5-HT2A receptor.
Psilocybin has been the subject of extensive clinical research, particularly since the early 2000s. Key findings include:
The FDA has granted Breakthrough Therapy designation to psilocybin for treatment-resistant depression, accelerating the path toward potential approval.
Psilocybin remains a Schedule I controlled substance under federal law in the United States, meaning it is classified as having no accepted medical use and high potential for abuse. However, this classification is increasingly at odds with scientific evidence. Oregon became the first state to legalize psilocybin therapy in 2020 (Measure 109), and Colorado followed with Proposition 122 in 2022. Several cities have decriminalized psilocybin possession, and more states are considering similar measures. Internationally, legal status varies widely—some countries permit traditional use, while others maintain strict prohibition.
Understanding psilocybin is fundamental to understanding magic mushrooms and their effects. As the primary psychoactive compound (via its conversion to psilocin), psilocybin is responsible for the therapeutic potential that has generated so much research interest. Knowing how it works—as a prodrug that converts to psilocin, which then acts on serotonin receptors—helps explain why effects take 30-60 minutes to onset and why different strains with different psilocybin concentrations produce different intensity experiences. As legal access expands through programs like Oregon's Measure 109, understanding psilocybin becomes increasingly relevant for anyone considering therapeutic use.