How does licorice root work in the body?

Licorice root's primary active compound, glycyrrhizin, inhibits the enzyme 11-beta-hydroxysteroid dehydrogenase, which converts cortisol to cortisone. This leads to increased cortisol levels, producing anti-inflammatory and mineralocorticoid effects. The herb also contains flavonoids like liquiritin and glabridin that contribute antioxidant and spasmolytic properties. In TCM theory, licorice tonifies spleen qi and harmonizes other herbs in formulas. Evidence Level: B.

What medications should not be taken with licorice root?

Licorice root interacts with several medication classes. It may potentiate corticosteroids and diuretics, increasing hypokalemia risk. It can reduce effectiveness of antihypertensive medications by raising blood pressure. Licorice also interacts with digoxin, warfarin, and oral contraceptives. Avoid combining with potassium-wasting diuretics, MAO inhibitors, or blood pressure medications. Consult a healthcare provider before use if taking prescription medications. Evidence Level: B.

What is the recommended dosage for licorice root?

Traditional TCM dosages range from 3-12 grams of dried root in decoction form daily. For deglycyrrhizinated licorice (DGL) extract, typical doses are 200-500mg daily for digestive support. Whole licorice should not be used long-term at high doses due to pseudoaldosteronism risk. DGL preparations are safer for extended use as they contain minimal glycyrrhizin. Always follow product labeling or consult a qualified practitioner. Evidence Level: B.

Is licorice root safe to take during pregnancy?

Licorice root is considered unsafe during pregnancy. Research suggests that consuming large amounts of licorice during pregnancy may be associated with preterm birth, lower birth weight, and potential effects on fetal brain development. Glycyrrhizin can cross the placenta and affect fetal development. Pregnant women should avoid licorice supplements and limit consumption of licorice-containing foods. Evidence Level: B.

What are the side effects of taking licorice root long-term?

Long-term or high-dose licorice consumption can cause pseudoaldosteronism, characterized by hypokalemia (low potassium), elevated blood pressure, and edema (fluid retention). Other side effects include headache, fatigue, and muscle weakness. These effects are primarily due to glycyrrhizin content. People with hypertension, kidney disease, heart failure, or existing edema should avoid licorice root. DGL extracts have minimal glycyrrhizin and lower side effect risk. Evidence Level: B.

Licorice Root TCM (Glycyrrhiza uralensis)

PubMed-compiled information sheet

This sheet was compiled from PubMed (NIH) abstracts using AI assistance. Every factual claim is cited to a real PubMed article (see the source list). It has not yet been human-reviewed — confirm with a healthcare provider before use.

Compiled from 30 PubMed articles · model: gemma4:31b

Summary

Glycyrrhiza uralensis (Gan-Cao) is a widely used medicinal herb in traditional Chinese medicine known for its diverse pharmacological activities, including anti-inflammatory, antioxidant, and antitumor effects [PMID:39625590, PMID:41390848].

Background

Licorice, known as Gan-Cao in China, is derived from the dried roots and rhizomes of Glycyrrhiza uralensis, G. glabra, and G. inflata [PMID:33309652, PMID:36067839]. It is recorded in the pharmacopoeias of China, Japan, the US, and Europe [PMID:36067839].

Traditional uses

It is extensively applied in traditional Chinese medicine (TCM) prescriptions, appearing in approximately 60% of them [PMID:33309652]. Traditional uses include heat clearing, detoxifying effects, cough relief, and phlegm elimination [PMID:33343964], as well as moderating the characteristics of toxic herbs [PMID:25557030].

Active compounds

The main bioactive constituents are triterpene saponins (including glycyrrhizic acid and 18β-glycyrrhetinic acid), flavonoids (such as isoliquiritigenin and liquiritin), and polysaccharides [PMID:18703197, PMID:40450977, PMID:33343964]. Other identified compounds include pterocarpenes like glycyrrhizol A and B [PMID:16441081].

Mechanism of action

Mechanisms include the activation of the Nrf2 signaling pathway for detoxification [PMID:25557030], activation of the Wnt/β-catenin pathway to restore tight junctions in colonic epithelium [PMID:40450977], and modulation of the MAPK/PI3K/AKT signaling pathway to attenuate myocardial fibrosis [PMID:39617235]. Polysaccharides may act through TLR4 and downstream p38, JNK, and NF-κB pathways for immunostimulation [PMID:32030319].

Clinical evidence

Evidence BPeriodontal disease

A mouthwash containing G. uralensis extract was evaluated for its effectiveness on periodontal pathogens in a randomized controlled trial [PMID:40413479]

Evidence BAllergic asthma (pediatric)

G. uralensis was compared to montelukast regarding the expression of T-bet and GATA-3 genes [PMID:35809275]

Evidence DSARS-CoV-2 infection

Triterpenoids licorice-saponin A3 and glycyrrhetinic acid potently inhibited infection in vitro [PMID:35116174]

Evidence DUlcerative colitis

18β-glycyrrhetinic acid protected colonic epithelium in rat models [PMID:40450977]

Evidence DAlzheimer's Disease

Glycyrrhizic acid targeted the JNK signaling pathway to reduce microglial apoptosis and inflammation in vitro [PMID:40605371]

Drug interactions

Licorice acts as a 'guide drug' in clinic, and its interaction with other ingredients in herbal formulas should be considered [PMID:31931596].

Evidence summary

The evidence consists primarily of in vitro studies, animal models (rats, mice, chickens), and a limited number of clinical trials. There is strong chemical characterization data, but clinical efficacy for human diseases requires more high-level evidence.

PubMed sources

1.PMID: 39823802 (2025) — Anti-colorectal cancer actions of Glycyrrhiza uralensis Fisch. and its underlying mechanism via HPLC integration and network pharmacological approaches. · Phytomedicine : international journal of phytotherapy and phytopharmacology
2.PMID: 33309652 (2021) — Recent advances in chemical analysis of licorice (Gan-Cao). · Fitoterapia
3.PMID: 36067839 (2022) — Chemical analysis of the Chinese herbal medicine licorice (Gan-Cao): An update review. · Journal of ethnopharmacology
4.PMID: 18703197 (2009) — Chemical analysis of the Chinese herbal medicine Gan-Cao (licorice). · Journal of chromatography. A
5.PMID: 39101144 (2024) — In vivo pharmacokinetics of Glycyrrhiza uralensis polysaccharides.

Licorice Root TCM

Sources & Citations

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Summary

Background

Traditional uses

Active compounds

Mechanism of action

Clinical evidence

Drug interactions

Evidence summary

PubMed sources

Government sources

Licorice Root TCM

Sources & Citations

Related Herbs

Marshmallow Leaf

Slippery Elm

Ginger

Summary

Background

Traditional uses

Active compounds

Mechanism of action

Clinical evidence

Drug interactions

Evidence summary

PubMed sources

Government sources