# Teonanácatl (Psilocybe mexicana)

**Psilocybe mexicana*, *P. cubensis*, *P. semilanceata*; Nahuatl, “flesh of the gods”*

**Known today as.** Small brown mushrooms that stain blue when bruised.

Kind: Fungus  
Poisoning: Psilocybin (https://thethinkingpress.org/materia-medica/poisons/psilocybin)

> **Caution.** Profoundly psychoactive; illegal in most places.

## What was it used for?

Eaten in sacred healing ceremonies in Mexico before and after the conquest.

## What does modern science say?

Psilocybin is being tested, with encouraging early results, for treatment-resistant depression; it remains a controlled drug in most countries.

## Pharmacognosy and toxicology

- **psilocybin**: a prodrug
- **psilocin**: the active form, a serotonin 2A agonist

**Mechanism.** Psilocin acts at the serotonin 2A receptors of the cortex.

**Dose.** Effects from about 10 mg of psilocybin; no fatal dose is established.

**Standing.** A controlled substance; licensed for depression in Australia from 2023 under supervision, and in clinical trials elsewhere.

## What lore surrounds it?

The Spanish friar Bernardino de Sahagún recorded the Aztec use of *teonanácatl*. In 1957 R. Gordon Wasson described in *Life* magazine the ceremony of the Mazatec healer María Sabina, and in 1958 Albert Hofmann isolated psilocybin.

## Sources

- Bernardino de Sahagún, *Florentine Codex*.
- Hofmann, A., et al. (1958). Psilocybin, ein psychotroper Wirkstoff aus dem mexikanischen Rauschpilz.
- Griffiths, R. R., et al. (2006). *Psychopharmacology* 187.

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*Teonanácatl.* In *Materia Medica*, edited by B. C. P. Statema. Version 1, revised 2026-09-25. The Thinking Press. https://thethinkingpress.org/materia-medica/teonanacatl

Historical description, not medical advice.