Tansy
Tanacetum
- Known today as
- Tanacetum vulgare.
- Kind
- Plant, in 3 older authorities
- Constituents
- thujone, camphor, parthenolide
- Earliest authority here
- Charlemagne and Hildegard (1098–1179)
- In other databases
- Plants of the World Online search · GBIF search · Wikidata search
Revised October 1, 2026: Tradition, lore, modern assessment, and sources extended. Version 1, first published September 25, 2026.
Caution. Poisonous in quantity.
Tansy: what was it used for?
Against worms and to provoke the menses; eaten at Easter in the “tansy” pudding.
Tansy: foraging it in the Midwest
- Part
- Flowers
- When
- Late summer
The Flambeau Ojibwe had no name of their own for it, saying it came from the south and was good for fevers; the yellow flowers went into the odorous hunting mixture smoked to attract deer. A roadside escape.
After Smith. All the foragables of the Midwest. Historical record, not a field guide: identify before you gather, and read the whole entry.
Tansy: how is it taken as a tea?
An ounce to a pint of boiling water, a teacupful night and morning fasting, to expel worms in children; in Scotland a half to one teaspoonful of the dried flowers and seeds for gout; an old country tea for fever.
All the herbal teas of the database. Historical directions, not medical advice.
Tansy: what does modern science say?
Its oil is rich in thujone, a nerve poison; it has caused deaths as an abortifacient. The oil is up to nine-tenths thujone, which excites the brain to convulsions, and the deaths were from women taking the oil to end pregnancies; a cup of the tea is far below that, but the herb is kept out of foods in most countries. Its old use against flies and lice has some truth: the oil repels insects in the laboratory.
Tansy: is it poisonous?
Yes, in some form or dose. Poisonous in quantity. Its poisoning is convulsant terpenes (thujone, pinocamphone, camphor): Minutes to an hour from the oils. Historical description, not medical advice; in a poisoning, call a poison centre.
Pharmacognosy & Toxicology
- Constituents
- Mechanism
- Thujone blocks the GABA-A receptor and provokes convulsions.
- Checked against ChEMBL
- thujone: No measurement in ChEMBL for “blocks the GABA-A receptor” (15 activities recorded, none against the target named); the line rests on its references.
- Toxic dose
- The oil in teaspoonfuls has killed; the herb in food is restricted.
- Syndrome
- Convulsant terpenes (thujone, pinocamphone, camphor)
- Standing
- Thujone is limited in foods and drinks in the European Union and the United States.
- Höld, K. M., et al. (2000). PNAS 97. Verified against its record · doi:10.1073/pnas.97.2.525
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.
Tansy: what lore surrounds it?
Its name preserves a wish: “tansy” descends through Old French and Late Latin from the Greek athanasia, “immortality,” most likely for the plant’s own persistence in the garden, though the coincidence with a plant so toxic in quantity has invited the darker reading.
In New England tansy was packed into coffins and rubbed on meat against the flies, and the dead were laid out on it; a tansy wreath marked a grave. Pliny’s immortality is the Greek athanasia, and the herb that preserved corpses may have earned the name that way.
Tansy: what did the older authorities say?
- Charlemagne and Hildegard
- The Capitulare de villis orders tansy grown on the imperial farms, and Hildegard of Bingen gives it for the stomach and the catarrh; the Benedictines of St Gall kept it.
- The tansy of Easter
- A pudding of eggs, cream, and tansy juice was eaten at Easter in England from the fifteenth century, in memory of the bitter herbs of Passover and to clear the body after the salt fish of Lent; Pepys ate it.
- Culpeper
- Gives it for the womb, to help conception and prevent miscarriage, and bruised and laid on the navel against worms.
Sources
- Grieve, M. (1931). A Modern Herbal. Read in part · the text read
- Online Etymology Dictionary, “tansy.” Book, seen in reviews
- Capitulare de villis (c. 800). Book, seen in reviews
- Grieve, M. (1931). A Modern Herbal, “Tansy.” Book, seen in reviews
Verification
- Checked
- October 1, 2026
- Passes
- Every sentence read against its sources, in the fifty-entry sample
- 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
- The mechanism read against ChEMBL (ChEMBL 37): curated mechanisms and measured activity
- Sources
- 5 cited: 1 read in part, 1 verified against its record, 3 book, seen in reviews.
- 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 1, 2026
- Chicago
“Tansy.” In Materia Medica, edited by B. C. P. Statema. Version 1. The Thinking Press, 2026–. Last modified October 1, 2026. https://thethinkingpress.org/materia-medica/tansy.
- MLA
“Tansy.” Materia Medica, edited by B. C. P. Statema, version 1, The Thinking Press, 1 Oct. 2026, thethinkingpress.org/materia-medica/tansy. Accessed 8 Oct. 2026.
- APA
Tansy. (2026, October 1). In B. C. P. Statema (Ed.), Materia medica (Version 1). The Thinking Press. Retrieved October 8, 2026, from https://thethinkingpress.org/materia-medica/tansy
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See Also
Poisoned alike: convulsant terpenes (thujone, pinocamphone, camphor)
Wormwood, oil of · Sage · Camphor · Rosemary · Hungary water · Mugwort · Hyssop · Mint, oil of · the syndrome, with all of them →
Sharing thujone, camphor, parthenolide
Artemisia abrotanum · The amulet herbs · Vinegar of the four thieves · Tanacetum parthenium
Also in Hildegard of Bingen
Galangal in Hildegard of Bingen · The precious stones in Hildegard of Bingen · Hop in Hildegard of Bingen · everything Hildegard of Bingen names →
Also in Nicholas Culpeper
Toadflax in Nicholas Culpeper · Tormentil in Nicholas Culpeper · Solomon’s seal in Nicholas Culpeper · everything Nicholas Culpeper names →
Drawing on the same sources: Grieve
Nearby in the alphabet
Tamarind (The pod pulp of Tamarindus indica) · Teasel (Dipsacus fullonum) · Teonanácatl (Small brown mushrooms that stain blue when bruised) · Sweet flag (Acorus calamus) · Terra sigillata (A clay dug on the island of Lemnos and stamped with a seal) · Sweet almond, oil of (Oil pressed from sweet almonds)
Historical description, not medical advice.