Jalap
Jalapa; the root of Xalapa
- Known today as
- Ipomoea purga, a Mexican morning glory whose tuber was shipped from the town of Xalapa.
- Kind
- Plant
- Constituents
- convolvulin, jalapin
- Poisoning
- Gastrointestinal irritants
- In other databases
- Plants of the World Online search · GBIF search · Wikidata search
Caution. A violent purge.
Jalap: what was it used for?
A strong purge, taken up in Europe in the seventeenth century and in every medicine chest by the eighteenth.
Jalap: what does modern science say?
Its resin is a drastic purgative; it has no place in medicine now.
Jalap: is it poisonous?
Yes, in some form or dose. A violent purge. Its poisoning is gastrointestinal irritants: Thirty minutes to three hours: the short latency is reassuring, since the deadly syndromes come later. Historical description, not medical advice; in a poisoning, call a poison centre.
Pharmacognosy & Toxicology
- Constituents
- Mechanism
- As scammony.
- Toxic dose
- Drastic; deaths in children.
- Syndrome
- Gastrointestinal irritants
- Standing
- Removed from the pharmacopoeias in the twentieth century.
- Pomet, P. (1694). Histoire générale des drogues. Book, seen in reviews
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.
Jalap: what lore surrounds it?
Benjamin Rush’s purging pills of calomel and jalap, his “thunderclappers,” went west with Lewis and Clark in 1804.
In Their Own Words
The 1911 Britannica says jalap had been known in Europe since the beginning of the seventeenth century and takes its name from the city of Jalapa in Mexico, near which it grows.
“Jalap has been known in Europe since the beginning of the 17th century, and derives its name from the city of Jalapa in Mexico, near which it grows,”
Encyclopædia Britannica, eleventh edition: Jalap, Jalap. The 1911 Encyclopædia Britannica, as transcribed on Wikisource. The text, read in full
Mrs Grieve says jalap makes a safe purge for children given in sugar or jam, and has been used so with calomel or wormwood against worms.
“Jalap forms a safe purge for children, being given in sugar or jam to disguise the taste, and has been used thus with calomel or wormwood as a vermifuge.”
Mrs. M. Grieve, A Modern Herbal: Bindweed, Jalap, Bindweed, Jalap, Medicinal Action and Uses. The text of A Modern Herbal as published on botanical.com. The text, read in full
For worms, Buchan names jalap and calomel as the best purge for an adult.
“The best purge for an adult is jalap and calomel. Five and twenty or thirty grains of the former with six or seven of the latter, mixed in syrup, may be taken early in the morning, for a dose.”
William Buchan, M.D., Domestic Medicine: or, a Treatise on the Prevention and Cure of Diseases by Regimen and Simple Medicines. With an Appendix, containing a Dispensatory for the Use of Private Practitioners, Of worms, Medicine. London: printed for A. Strahan, T. Cadell, 1791 (Project Gutenberg eBook #74359). The text, read in part
Each passage is quoted from the text named, which the press fetched and read, and was checked word for word against a fresh copy of it; the link opens that copy. Passages are given as printed, without the editors’ footnote numbers, and with words broken across lines joined.
Sources
- Pomet, P. (1694). Histoire générale des drogues (English, A Compleat History of Druggs, 1712). Read in part · the text read
- Grieve, M. (1931). A Modern Herbal, “Jalap.” Book, not indexed
Verification
- Checked
- October 1, 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
- Sources
- 3 cited: 1 read in part, 1 book, seen in reviews, 1 book, not indexed.
- 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 30, 2026
- Chicago
“Jalap.” In Materia Medica, edited by B. C. P. Statema. Version 1. The Thinking Press, 2026–. Last modified September 30, 2026. https://thethinkingpress.org/materia-medica/jalap.
- MLA
“Jalap.” Materia Medica, edited by B. C. P. Statema, version 1, The Thinking Press, 30 Sept. 2026, thethinkingpress.org/materia-medica/jalap. Accessed 8 Oct. 2026.
- APA
Jalap. (2026, September 30). In B. C. P. Statema (Ed.), Materia medica (Version 1). The Thinking Press. Retrieved October 8, 2026, from https://thethinkingpress.org/materia-medica/jalap
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See Also
Poisoned alike: gastrointestinal irritants
Livid pinkgill · Jack-o’-lantern · Meadow saffron · Honey fungus · Melon root · Cyclamen, greater · Mistletoe · Common earthball · the syndrome, with all of them →
Sharing jalapin
Drawing on the same sources: Pomet, Grieve
Marjoram and jasmine · Isinglass · Mastic · Jelly ear · Ipecacuanha · Juniper · the bibliography →
Nearby in the alphabet
James’s powder (secret in its making) · Iva (Ajuga iva) · Jet, oil of (a dense variety of lignite) · Jewelweed · Iron and steel (given as filings in wine, as its rust, or in chalybeate spring waters)
Historical description, not medical advice.