# Unicorn’s horn (Monodon monoceros)

*Alicorn; *cornu unicornis**

**Known today as.** Almost always the tusk of the narwhal, *Monodon monoceros*.

Kind: Animal

## What does modern science say?

No effect as an antidote. The tusk is a tooth, the left upper canine of the male grown through the lip in a spiral, up to nine feet long, and in 2014 it was shown to be threaded with nerves that sense the salt and temperature of the sea. Ole Worm’s dissertation of 1638 showed the horns to be narwhal teeth, though apothecaries sold chips and dust of “unicorn” as antidotes until the eighteenth century.

## Pharmacognosy and toxicology

- **dentine**: the narwhal tusk, which the horn was
- **collagen**: 

**Mechanism.** A narwhal’s tooth, sold at a little over ten times its weight in gold as an antidote and a test for poison; Paré, testing it on toads and in his practice, never found it do anything against poison. Ambroise Paré doubted it in 1582 and the Danish professor Ole Worm proved its source in 1638.

**Dose.** Inert.

**Standing.** A curiosity; the narwhal is protected and its tusk trade regulated under CITES Appendix II.

## What lore surrounds it?

Believed to sweat in the presence of poison, it was dipped into the cups of kings and sold, ground, for vast sums.

The unicorn throne of the Danish kings is made of it; the Tsar Theodore Ivanovitch was crowned at Moscow in 1584 holding a staff of unicorn’s horn beset with stones, bought for seven thousand marks; and the Horn of Windsor, kept by Elizabeth I’s command in her wardrobe of robes, was valued by the traveller Hentzner in 1598, if his Latin is to be trusted, at a hundred thousand pounds. Apothecaries sold the “true unicorn’s horn,” *verum cornu monocerotis*, at a little over ten times its weight in gold, and physicians prescribed it, a few grains to a scruple, against poison, the plague, and the falling sickness.

## What did the older authorities say?

**Ctesias.** The Greek physician, in his *Indica* as abridged by Photios, described wild asses of India with a horn on the forehead; those who drank from cups made of it were attacked neither by convulsions nor by epilepsy, nor affected by poisons.

**Ole Worm.** The Danish professor, in a Latin dissertation delivered at Copenhagen in 1638, showed that the alicorns treasured all over Europe were not horns at all but the teeth of narwhals.

**The Norse traders.** Probably began the trade in narwhal tusks from Greenland, which through European channels reached markets in the Middle East and East Asia; Scandinavian fishermen kept the secret of their source for at least five centuries.

**Ambroise Paré.** Doubted the horn in 1582: having tried it many times he had never known it to work; a toad kept three days in water in which the horn had steeped came out as lively as when it went in; and the tale that it saves a poisoned pigeon or chicken he called false. The horns he tested were those of Saint-Denis, of the King, and of the Paris merchants who sold them at great price.

## Sources

- Ctesias, *Indica*.
- Ambroise Paré, *Discours de la licorne* (1582).
- Paré, A. (1582). *Discours de la licorne*.
- Nweeia, M. T., et al. (2014). “Sensory ability in the narwhal tooth organ system.” *Anatomical Record* 297.
- Wikipedia, “Unicorn horn.”
- Wikipedia, “Narwhal.”
- Shepard, O. (1930). *The Lore of the Unicorn*. Houghton Mifflin.
- Paré, A. (1582). *Discours de la mumie, de la licorne, des venins et de la peste*.

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

Historical description, not medical advice.