psilocybin

American  

[sil-uh-sahy-bin, sahy-luh-] / ˌsɪl əˈsaɪ bɪn, ˌsaɪ lə- /

noun

Pharmacology.

1. a hallucinogenic crystalline solid, C 1 2 H 1 7 N 2 O 4 P, obtained from the mushroom Psilocybe mexicana.

---

psilocybin British  

/ ˌsaɪlə-, ˌsɪləˈsaɪbɪn /

noun

1. a crystalline phosphate ester that is the active principle of the hallucinogenic fungus Psilocybe mexicana. Formula: C 12 H 17 N 2 O 4 P

---

psilocybin Scientific  

/ sĭl′ə-sī′bĭn,sī′lə- /

1. A hallucinogenic compound obtained from certain mushrooms, especially of the genus Psilocybe. Chemical formula: C ₁₂ H ₁₇ N ₂ O ₄ P.

---

Etymology

Origin of psilocybin

1955–60; < New Latin Psilocyb ( e ) genus of mushrooms (< Greek psīló ( s ) bare + kýbē head) + -in ²

Example Sentences

See Examples For:

psilocybin

Although none of the participants had a diagnosed mental health condition, the findings may offer clues about why psilocybin has shown therapeutic potential for depression, anxiety, and addiction.

From Science Daily ● Jul. 22, 2026

Compass Pathways confirmed an FDA priority voucher for its psilocybin candidate.

From Barron's ● Apr. 24, 2026

Dr. Steven Locke, a former Harvard Medical School psychiatry professor, wrote in an email that the question of whether psilocybin has any medical applications “remains controversial.”

From Los Angeles Times ● Aug. 21, 2025

There are few published clinical trials of psilocybin therapy for chronic pain, although many are ongoing, including a pilot study for fibromyalgia conducted by our team at the University of Michigan.

From Salon ● May 13, 2024

Another patent lays claim to a specific, microscopic structure found in Compass’ synthetic psilocybin, which the company claims is uniquely suited for mass production.

From Seattle Times ● Feb. 3, 2024