Review: Pharmacology of Psilocybin by Torsten Passie et al.

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Article ID: 11075934


This paper delves into the pharmacological properties of psilocybin, the main psychoactive component in certain hallucinogenic mushrooms. The study offers insights on psilocybin's historical and current uses, its effects on human physiology and psychology, and its metabolic pathway.

Key Findings:


Psilocybin is a primary alkaloid in certain mushroom species and is a major drug of hallucinogenic abuse worldwide.
Despite its experimental medical use in the 1960s, little pharmacological data about psilocybin was available.


Psilocybin is a substituted indolealkylamine and is classified as a hallucinogenic tryptamine.
Swiss chemist Albert Hofmann isolated psilocybin from Central American mushrooms in 1957, and it was synthetically produced in 1958.

Psychic Effects:

At medium dosage (12-20 mg orally), psilocybin can produce an altered state of consciousness, stimulating affect, introspection, and an enhanced ability for Freudian primary processes, such as dream-like experiences.
Perceptual changes, synaesthesia, affective activation, and alterations in thought and time sense are among its prominent effects, lasting 3 to 6 hours.

Somatic Effects:

Effects include mydriasis, heart rate irregularities, piloerection, and mild hypertonic effects.
It has no significant long-term toxic effects on human organs.
In human trials, psilocybin affected heart rate and blood pressure but did not significantly alter cortisol, prolactin, or growth hormone levels.
There's no evidence of genetic aberrations caused by psilocybin in mouse micronucleus tests.


Around 50% of psilocybin is absorbed after oral intake, and its isotope is almost uniformly distributed throughout the body.
Four metabolites of psilocybin have been identified, with psilocin being the primary one.
Psilocybin appears to act as a prodrug, converting largely into psilocin before entering the systemic circulation, making psilocin the main active substance.
Oral administration of psilocybin results in detectable levels in the plasma within 20-40 minutes, with effects occurring at plasma levels of 4-6 mg/ml.
Full effects are observed within 70-90 minutes and last around 3 to 6 hours.


The paper presents a comprehensive review of psilocybin's pharmacological properties. It highlights psilocybin's potential for abuse but also underscores its intriguing psychological effects, paving the way for further investigations into its potential therapeutic applications. The research, while detailed, calls for additional studies to provide a more exhaustive understanding of psilocybin's effects and potential uses in medical treatments.

Go to Article: 11075301 - PiHKAL: The Chemical Story - A.Shulgin & A.Shulgin