Unicorn’s horn
Alicorn; cornu unicornis
- Known today as
- Almost always the tusk of the narwhal, Monodon monoceros.
- Kind
- Animal, in 4 older authorities
- Constituents
- dentine, collagen
- Earliest authority here
- Ctesias (5th century BC)
- In other databases
- GBIF search · Wikidata search
Revised October 3, 2026: Tradition, lore, modern assessment, and sources extended. Checked against its sources, each read in full, in part, or in its abstract. Version 1, first published September 25, 2026.
Unicorn’s horn: 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 & Toxicology
- Constituents
- 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.
- Toxic dose
- Inert.
- Standing
- A curiosity; the narwhal is protected and its tusk trade regulated under CITES Appendix II.
- Shepard, O. (1930). The Lore of the Unicorn. Houghton Mifflin. Read in part · the text read
- Paré, A. (1582). Discours de la mumie, de la licorne, des venins et de la peste. Primary text
Constituent names open the compound’s record at PubChem, and “ChEMBL” beside a name opens its record at ChEMBL, the European Bioinformatics Institute’s database of bioactive molecules. Where a mechanism line was checked against ChEMBL (ChEMBL 37, read 1 October 2026), the check is shown with the measured value and its source paper, or says plainly that nothing has been measured. Doses are as the references give them, for description only; this is not medical advice. Each source carries the result of its check against Crossref, PubMed, or the authority’s page: see Verification.
What Medicine Makes of It
- The Universal AntidoteBezoar, unicorn, and theriac against every poison, and what replaced them.
Unicorn’s horn: 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.
Unicorn’s horn: 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. Read in part · the text read
- Ambroise Paré, Discours de la licorne (1582). Read in part · the text read
- Paré, A. (1582). Discours de la licorne. Read in part · the text read
- Nweeia, M. T., et al. (2014). “Sensory ability in the narwhal tooth organ system.” Anatomical Record 297. Abstract read · the text read
- Wikipedia, “Unicorn horn.” Read in full · the text read
- Wikipedia, “Narwhal.” Read in full · the text read
In Symbols of the Psyche
The Unicorn: what it stood for in alchemy and in analytical psychology.
Verification
- Checked
- October 1, 2026, and October 3, 2026
- Passes
- Every sentence read against its sources, in the pass over the remaining 343 entries
- The Standing line checked against the authority it names (EMA, WHO, FDA, CITES, Commission E)
- Every dated or regulatory claim checked by category across the database
- Every source read, in full, in part, or in its abstract, and every sentence checked against what was read (October 3, 2026)
- Sources
- 8 cited: 2 read in full, 4 read in part, 1 abstract read, 1 primary text. 1 with the abstract on file.
- Corrections
- None were needed.
What was checked, how, and what was found is set out on the Verification page. A checked source is one whose record was found; it does not make the entry medical advice.
Cite This Entry
Version 1 · first published September 25, 2026 · last revised October 3, 2026
- Chicago
“Unicorn’s horn.” In Materia Medica, edited by B. C. P. Statema. Version 1. The Thinking Press, 2026–. Last modified October 3, 2026. https://thethinkingpress.org/materia-medica/unicorns-horn.
- MLA
“Unicorn’s horn.” Materia Medica, edited by B. C. P. Statema, version 1, The Thinking Press, 3 Oct. 2026, thethinkingpress.org/materia-medica/unicorns-horn. Accessed 8 Oct. 2026.
- APA
Unicorn’s horn. (2026, October 3). In B. C. P. Statema (Ed.), Materia medica (Version 1). The Thinking Press. Retrieved October 8, 2026, from https://thethinkingpress.org/materia-medica/unicorns-horn
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See Also
Sharing collagen
Also in Ambroise Paré
Bezoar stone in Ambroise Paré · Mummy in Ambroise Paré · everything Ambroise Paré names →
Drawing on the same sources: Wikipedia
Viper · Toadflax · Wax · the bibliography →
Nearby in the alphabet
Valerian (Valeriana officinalis) · Turpentine · Verbena (Verbena officinalis) · Turmeric (of the ginger family, whose root is deep yellow within) · Verdigris (the green rust of copper) · Turkey tail (banded bracket of dead wood, common worldwide) · The vernicle (leaving his image) · Truffle
Historical description, not medical advice.