# Toad

**Bufo**

**Known today as.** The common toad, dried, powdered, or worn.

Kind: Animal  
Poisoning: Cardiac glycoside poisoning (https://thethinkingpress.org/materia-medica/poisons/cardiac-glycoside)  
Toxic: yes

> **Caution.** Toad secretions are poisonous.

## What was it used for?

Worn against the plague, and laid dried on the plague-sore to draw the poison into itself.

## What does modern science say?

Toad skin secretes bufotoxins, which act on the heart. The parotoid glands behind the eyes secrete bufotoxins, which act on the heart like digitalis and have killed people who took *chansu* or Caribbean toad preparations as aphrodisiacs; the Colorado River toad, *Incilius alvarius*, secretes 5-MeO-DMT, a hallucinogen now smoked in ceremonies and studied for depression, and “toad licking” has drawn the attention of the press since its smoking was popularised by a pamphlet of 1983. Dogs that attack the Colorado River toad have been paralysed or killed.

## Pharmacognosy and toxicology

- **bufotalin**: a bufadienolide
- **bufotenine**: 
- **5-MeO-DMT**: in *Incilius alvarius*

**Mechanism.** The bufadienolides are potent inhibitors of the Na+/K+ ATPase, and their poisoning resembles digitalis toxicity; 5-MeO-DMT binds strongly to the 5-HT2 and 5-HT1A serotonin receptors.

**Dose.** Toad-venom “aphrodisiacs” have killed within hours; digoxin-specific Fab fragments may save life.

**Standing.** *Chansu* is in the Chinese pharmacopoeia; 5-MeO-DMT is in clinical trials for depression.

## What lore surrounds it?

The witch’s familiar, the toad was also a healer: dried and laid on the plague-sore, it was held to draw the poison into itself. See [Toadstone](https://thethinkingpress.org/materia-medica/toadstone).

In China the three-legged money toad brings fortune, and the dried venom, *chansu*, is in the heart medicines of the pharmacopoeia.

## What did the older authorities say?

**Van Helmont.** Recommended an amulet made from a toad dried and powdered as a defense against the plague.

**Pliny.** Of the “bramble-frog,” which his translators take for the toad, reports that a bone from its right side cools boiling water, and, tied to the patient in fresh lamb’s skin, assuages fevers and checks amorous propensities; authors, he says, vie with one another in marvellous stories of it.

**The witch trials.** Among the familiars that accused witches described, the toad was one of the commonest, kept in a pot lined with wool and fed on milk, bread, meat, or blood; Shakespeare’s witches begin their cauldron with the toad “that under cold stone days and nights has thirty-one sweltered venom sleeping got.”

## Sources

- Van Helmont, J. B. (1644). *Tumulus pestis*.
- Shakespeare, *Macbeth* IV.i.
- Pliny, *Natural History* XXXII.
- Wikipedia, “Bufotoxin.”
- Wikipedia, “Colorado River toad.”
- Wikipedia, “Jin Chan.”
- Wikipedia, “Familiar.”
- Zou, D., et al. (2022). Bufadienolides originated from toad source and their anti-inflammatory activity. *Frontiers in Pharmacology* 13.
- Seynaeve, M., et al. (2026). Intranasal 5-MeO-DMT concomitant with SSRI for treatment-resistant depression: a proof-of-concept trial. *CNS Drugs*.
- Gowda, R. M., et al. (2003). “Toad venom poisoning.” *Heart* 89.

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*Toad.* In *Materia Medica*, edited by B. C. P. Statema. Version 1, revised 2026-10-03. The Thinking Press. https://thethinkingpress.org/materia-medica/toad

Historical description, not medical advice.