Licorice

Statema, B. C. P.

Plant

Licorice

Glycyrrhiza, “sweet root”; the Scythian root

Known today as: The root of Glycyrrhiza glabra.
Kind: Plant, in 3 older authorities
Constituents: glycyrrhizin, glycyrrhetinic acid, glabridin
Earliest authority here: Theophrastus (c. 371–c. 287 BC)
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. Large or daily amounts raise blood pressure and lower potassium.

Licorice: what was it used for?

For coughs, hoarseness, and the chest, and to sweeten bitter medicines.

Licorice: what does modern science say?

Glycyrrhizin soothes the throat, but in quantity it raises blood pressure and lowers potassium. Glycyrrhizin is fifty times sweeter than sugar and mimics the hormone that holds salt; a bag of licorice sweets a day can raise the blood pressure and drop the potassium far enough to stop the heart, and the United States Food and Drug Administration warned of it in 2017. A licorice extract stripped of glycyrrhizin is used for stomach ulcers.

Pharmacognosy & Toxicology

Constituents

glycyrrhizin ChEMBL
glycyrrhetinic acid ChEMBLits active metabolite
glabridin ChEMBL

Mechanism

Glycyrrhetinic acid blocks the enzyme that keeps cortisol from the kidney’s mineralocorticoid receptor, so the kidney retains salt and loses potassium.

Checked against ChEMBL

glycyrrhetinic acid: Measured, as the entry says (“blocks the enzyme that keeps cortisol from the mineralocorticoid receptor”): 11-beta-hydroxysteroid dehydrogenase type 2 (human), IC50 1.2 nM, CHEMBL3421600; 11-beta-hydroxysteroid dehydrogenase 1 (mouse), IC50 2 nM, CHEMBL2401669.

Toxic dose

Above about 100 mg of glycyrrhizin a day, which 50 g of sweets can hold, blood pressure rises and potassium falls; deaths from heart rhythm are recorded.

Standing

Approved in Europe as a traditional remedy for the chest and stomach; the FDA warned in 2017 against more than two ounces a day of black liquorice in those over forty.

Omar, H. R., et al. (2012). Therapeutic Advances in Endocrinology and Metabolism 3. Book, not indexed

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.

Licorice: what lore surrounds it?

Dominican friars are said to have brought the plant to Pontefract in Yorkshire, where the root grew in the castle grounds, and Pontefract cakes, stamped with the castle, were made from 1614; the sweet “Spanish” of the English north was licorice stick. Napoleon chewed it, and his blackened teeth were put down to it.

Licorice: what did the older authorities say?

Theophrastus: Says the Scythians could go eleven or twelve days without drinking by eating this root.
The Egyptians: Buried a store of licorice root in the tomb of Tutankhamun, and drank a sweet licorice water, mai sus, still sold in the streets of Cairo.
Dioscorides: Gives the juice of the root for the chest, the throat, and the burning of the stomach, and says it quenches thirst, as Theophrastus had said of the Scythians.

Sources

Theophrastus, Enquiry into Plants IX. Verified against its record · doi:10.4159/dlcl.theophrastus-enquiry_plants.1916
Omar, H. R., et al. (2012). “Licorice abuse: time to send a warning message.” Therapeutic Advances in Endocrinology and Metabolism 3. Verified against its record · doi:10.1177/2042018812454322

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
The mechanism read against ChEMBL (ChEMBL 37): curated mechanisms and measured activity

Sources

3 cited: 2 verified against its record, 1 book, not indexed. 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 1, 2026

Chicago: “Licorice.” 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/licorice.
MLA: “Licorice.” Materia Medica, edited by B. C. P. Statema, version 1, The Thinking Press, 1 Oct. 2026, thethinkingpress.org/materia-medica/licorice. Accessed 8 Oct. 2026.
APA: Licorice. (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/licorice

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