Cascara
Cascara sagrada, sacred bark; Rhamnus purshiana DC.; Rhamnus alnifolius Pursh; Frangula purshiana (DC.) A. Gray; in pharmacy Rhamni purshianae cortex
- Known today as
- The dried bark of Rhamnus purshiana, a small buckthorn tree of the family Rhamnaceae found, King’s Dispensatory says, from the Rocky Mountains west to the Pacific and north into British America, with leaves three to five inches long, small white flowers in close clusters, and a black fruit the size of a large pea. The bark comes in quills or curved pieces, brownish-grey outside, yellowish within, without odour and bitter. The European Medicines Agency’s assessment report explains why it is dried before use: the fresh bark holds anthrones that cause vomiting, which drying oxidises into forms free of that effect.
- Kind
- Plant, in 1 older authority
- Constituents
- cascarosides
- Poisoning
- The anthranoid purgatives
- Earliest authority here
- King’s American Dispensatory (1898)
- In other databases
- Plants of the World Online · GBIF · Wikidata
Caution. A stimulant laxative, for short use only: long use may impair the bowel’s function and bring dependence, loss of water and potassium, and a harmless darkening of the bowel lining. Not in pregnancy or breast-feeding, because of experimental evidence of genotoxic risk from some anthranoids and their passage into milk; not under twelve; not with bowel obstruction, appendicitis, inflammatory bowel disease, unexplained abdominal pain, or severe dehydration. Potassium loss can strengthen cardiac glycosides and interact with antiarrhythmics, and diuretics, corticosteroids, and liquorice add to it. The urine may turn yellow or red-brown. LiverTox finds it generally safe in recommended doses for a short time, but records several cases of liver injury, a few severe, after longer use of high doses; chronic overdose of anthranoid medicines may cause toxic hepatitis.
Cascara: what was it used for?
A laxative. LiverTox records that ‘cascara sagrada’ is Spanish for “sacred bark” and that it was used for centuries by Native Americans as a laxative. King’s Dispensatory says it was highly recommended on its introduction as a certain remedy for habitual constipation, a claim further trial had substantially sustained, though it acted best “where a tonic to the intestines is required,” producing semifluid stools “without irritating or griping.”
Cascara: what does modern science say?
The European Medicines Agency’s herbal committee accepts the bark on clinical evidence, as ‘well-established use,’ for short-term use in occasional constipation (monograph of 2020). Its assessment report requires at least 8 per cent of hydroxyanthracene glycosides, most of them cascarosides, the anthrone glycosides credited with the laxative action. It also found no clinical studies of cascara alone or in combination in a representative population with constipation, the laxative effect resting “mainly” on pharmacological data, expert opinion, and clinical experience.
Pharmacognosy & Toxicology
- Constituents
- cascarosidesmost of the hydroxyanthracene glycosides, at least 8 per cent required; the anthrone glycosides credited with the laxative action
- Mechanism
- A stimulant laxative of the anthranoid kind; the fresh bark holds emetic anthrones, which drying oxidises.
- Syndrome
- The anthranoid purgatives
- Standing
- European Union herbal monograph (2020): well-established use, for short-term use in occasional constipation.
- European Medicines Agency, Committee on Herbal Medicinal Products. European Union herbal monograph on Rhamni purshianae cortex (Cascara). EMA/HMPC/726270/2016, 6 May 2020. Read in full · the text read
- European Medicines Agency, Committee on Herbal Medicinal Products. Assessment report on Rhamni purshianae cortex. EMA/HMPC/909434/2019, 6 May 2020. Read in part · the text read
- LiverTox: Clinical and Research Information on Drug-Induced Liver Injury, “Cascara.” National Institute of Diabetes and Digestive and Kidney Diseases, updated 2017. NCBI Bookshelf. Read in full · the text read
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.
Cascara: what lore surrounds it?
King’s records that Mr James G. Steele reckoned the country producing the tree to extend over a thousand miles, and that the California buckthorn probably supplied part of the cascara sagrada of commerce.
Cascara: what did the older authorities say?
- King’s American Dispensatory (1898)
- “Cascara sagrada was discovered by an Eclectic physician, Dr. J. H. Bundy,” its virtues first extolled in Detroit in 1877; Parke, Davis & Co. introduced the fluid extract to the profession, and to their efforts, King’s judged, was due the drug’s widespread celebrity. The bark had long been known in domestic practice among western people as a mild cathartic.
Sources
- Felter, H. W., & Lloyd, J. U. (1898). King’s American Dispensatory, vol. 2, “Rhamnus Purshiana.” Internet Archive, kingsamericandis02kinguoft. Read in part · the text read
- European Medicines Agency, Committee on Herbal Medicinal Products. European Union herbal monograph on Rhamni purshianae cortex (Cascara). EMA/HMPC/726270/2016, 6 May 2020. Read in full · the text read
- European Medicines Agency, Committee on Herbal Medicinal Products. Assessment report on Rhamni purshianae cortex. EMA/HMPC/909434/2019, 6 May 2020. Read in part · the text read
- LiverTox: Clinical and Research Information on Drug-Induced Liver Injury, “Cascara.” National Institute of Diabetes and Digestive and Kidney Diseases, updated 2017. NCBI Bookshelf. Read in full · the text read
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
- 4 cited: 2 read in full, 2 read in part.
- 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.
Club members can point at a technical term in this entry, such as a constituent, an action, or a word of Jung’s, to read its definition from the source. The Club.
Cite This Entry
Version 1 · first published October 16, 2026
- Chicago
“Cascara.” In Materia Medica, edited by B. C. P. Statema. Version 1. The Thinking Press, 2026–. Last modified October 16, 2026. https://thethinkingpress.org/materia-medica/cascara.
- MLA
“Cascara.” Materia Medica, edited by B. C. P. Statema, version 1, The Thinking Press, 16 Oct. 2026, thethinkingpress.org/materia-medica/cascara. Accessed 17 Oct. 2026.
- APA
Cascara. (2026, October 16). In B. C. P. Statema (Ed.), Materia medica (Version 1). The Thinking Press. Retrieved October 17, 2026, from https://thethinkingpress.org/materia-medica/cascara
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See Also
Poisoned alike: the anthranoid purgatives
Cassia, flower of · Alder buckthorn · Compound fumitory · Yellow dock · Diacatholicon · Rhubarb · Hiera picra · Myrobalans · the syndrome, with all of them →
Drawing on the same sources: Felter
Chokecherry · Brewer’s yeast · Corn silk · the bibliography →
Nearby in the alphabet
Cassia wood (Cinnamomum aromaticum (long known as Cinnamomum cassia)) · Carmelite water (with lemon peel, nutmeg, coriander, and angelica, distilled in spirit) · Cardamom · Castor-oil plant, seeds of (Ricinus communis) · Caraway broth (Carum carvi) · Castoreum (The scent gland secretion of the beaver) · The Caravaca cross
Historical description, not medical advice.
