What is Licorice and Which Foods Contain It?
Licorice is the root of the Glycyrrhiza plant (primarily Glycyrrhiza glabra and Glycyrrhiza uralensis) that contains bioactive compounds including glycyrrhizin, which has significant mineralocorticoid effects and can cause serious adverse effects including hypertension, hypokalemia, and fluid retention. 1
What Licorice Is
Licorice is a plant root extract with multiple bioactive components:
- Primary active compound: Glycyrrhizin (also called glycyrrhizic acid), which is metabolized to glycyrrhetinic acid (GA) in the intestine 1
- Other bioactive compounds: Liquiritigenin, isoliquiritigenin, licochalcone A, glycycoumarin, and glabridin 1, 2
- Mechanism of action: These compounds inhibit 11β-hydroxysteroid dehydrogenase type 2, causing excess mineralocorticoid activity (pseudo-aldosteronism) 3, 4
Foods and Products Containing Licorice
Licorice is found in multiple commercial products:
Common Sources:
- Licorice juice - a popular beverage, especially during Ramadan fasting 1
- Licorice candy and confections - sweeteners in various foods 5, 4
- Food additives - used as a sweetener in processed foods 5
- Herbal teas and supplements - health food products 6
- Tobacco products - flavoring agent 2, 4
- Traditional medicines - used in various herbal preparations 2
Glycyrrhizin Content:
Commercial licorice extracts vary widely in glycyrrhizin content, ranging from 10.9% to 77.4% depending on the manufacturing process 5. This variability makes it difficult to predict exact exposure levels from different products.
Critical Safety Concerns
Serious Adverse Effects:
Long-term or high-dose licorice consumption causes potentially fatal complications including 1, 3:
- Hypertension (sometimes severe)
- Hypokalemia with metabolic alkalosis
- Fluid retention and edema
- Hypervolemia
- Secondary disorders from electrolyte imbalances
Specific Patient Populations to Avoid Licorice:
Patients with cirrhosis or chronic liver disease should avoid licorice due to risk of sodium retention, worsening edema, and exacerbation of ascites 1 (Grade C recommendation).
Patients on fludrocortisone or hydrocortisone replacement therapy must avoid licorice as it potentiates mineralocorticoid effects and can cause dangerous electrolyte imbalances 7.
Patients on immunosuppressive drugs (cyclosporine, methotrexate, cilostazol) should avoid licorice due to significant drug-drug interactions through CYP3A enzyme induction 1.
Drug Interactions:
Licorice affects multiple medications 1, 7:
- Reduces need for hydrocortisone and fludrocortisone (potentiates their effects)
- Increases methotrexate retention time
- Causes pseudoaldosteronism with cilostazol
- Interacts with cyclosporine through CYP3A metabolism
Clinical Pitfalls
The major challenge with licorice toxicity is that:
- Symptoms develop gradually with chronic consumption, making the connection to licorice less obvious
- Product labeling is inconsistent - glycyrrhizin content varies dramatically between products 5
- Patients may not recognize licorice in processed foods, candies, or herbal supplements
- Effects are dose-dependent but with high inter-individual variability 3, 4
When evaluating unexplained hypertension with hypokalemia and metabolic alkalosis, specifically ask about licorice consumption in all forms (candy, tea, juice, supplements, tobacco products). The diagnosis requires detailed dietary history, as patients often don't consider licorice a "medication" or significant dietary component.
Management is straightforward: stop all licorice consumption and provide symptomatic electrolyte correction 3. Effects are reversible upon discontinuation, but recovery may take time due to slow plasma clearance from enterohepatic cycling 3.