Gān Cǎo (甘草) — Licorice Root

On this page

1. Overview
2. Properties
3. Actions and indications
4. Key formulas
5. Modern research
6. Incompatibilities
7. Cautions and contraindications
8. Treatment at my clinic

1. Overview

Gān Cǎo (甘草) — Glycyrrhiza uralensis / inflata / glabra — is known in English as Licorice root / Liquorice root. It belongs to the category of Qi tonics / Harmonising herbs in the Chinese Materia Medica and is one of the most important and widely prescribed herbs in traditional Chinese medicine (TCM). It is used in Chinese herbal medicine both as a component of classical herbal formulas and as a significant individual herb in tailored prescriptions.

I prescribe Gān Cǎo as part of bespoke herbal formulas from pharmaceutical-grade granules sourced from Sun Ten in Taiwan — independently tested to the highest international quality and safety standards. Herbs are never prescribed individually outside a properly balanced formula; they are always combined with other herbs selected to match the patient’s individual TCM pattern. Online consultations are available for patients who cannot attend my clinic in person.

2. Properties

3. Actions and indications

Principal actions

1. Tonifies the Spleen and augments Qi
2. Moistens the Lungs and stops coughing
3. Clears Heat and resolves toxicity (raw form)
4. Moderates spasm and alleviates pain
5. Harmonises the actions of other herbs and moderates toxicity

Indications

1. Spleen Qi deficiency with fatigue, loose stools and shortness of breath
2. Cough and wheezing from multiple patterns (combined with appropriate herbs)
3. Carbuncles, sores and sore throats from Heat toxin (raw form)
4. Limb spasm and abdominal cramping (combined with Bai Shao in Shao Yao Gan Cao Tang)
5. Used in virtually every classical formula as a harmonising agent
6. Addison’s disease equivalent (adrenal insufficiency)

4. Key formulas containing Gān Cǎo

Gān Cǎo is an ingredient in many classical formulas. The following are among the most important:

• Si Jun Zi Tang
• Shao Yao Gan Cao Tang
• Zhi Gan Cao Tang
• Bu Zhong Yi Qi Tang

See the full Chinese herbal medicine formula directory for detailed information on all 88 classical formulas.

5. Modern research

Glycyrrhiza uralensis (Gan Cao) is the most commonly prescribed Chinese medicinal herb, present in the majority of classical formulas. Key bioactive constituents include glycyrrhizin, glycyrrhetinic acid, liquiritin, isoliquiritin and flavonoids. Glycyrrhizin has potent anti-inflammatory, antiviral and immune-modulating effects and inhibits the metabolism of cortisol, explaining the herb’s adrenal-supporting properties. Research confirms anti-inflammatory effects comparable to hydrocortisone, anti-ulcer effects protecting gastric mucosa, antiviral activity against influenza and SARS-CoV, hepatoprotective effects and oestrogen-modulating activity relevant to PCOS. Licorice extract is one of the most widely used pharmaceutical precursors in conventional medicine.

6. Incompatibilities

The classical Ming-dynasty texts Shi Ba Fan (Eighteen Antagonisms) and Shi Jiu Wei (Nineteen Mutual Inhibitions) record herb pairs that should not be combined. Modern practitioners treat these as strong cautions rather than absolute contraindications — classical training avoids the combinations except in carefully supervised low-dose protocols.

Gān Cǎo (甘草) Licorice Root should not normally be combined with:

• Gan Sui — per the Shi Ba Fan
• Da Ji — per the Shi Ba Fan
• Yuan Hua — per the Shi Ba Fan
• Hai Zao — per the Shi Ba Fan

7. Cautions and contraindications

Prolonged use of large doses of raw Gan Cao (particularly glycyrrhizin) can cause pseudohyperaldosteronism — oedema, hypertension and hypokalaemia. Avoid in patients with pre-existing hypertension, oedema and hypokalaemia. Honey-fried form (Zhi Gan Cao) is more tonifying and less likely to cause adverse effects. Use at standard formulary doses is extremely safe.

Pattern contraindications

Contraindicated in Excess patterns (acute Heat, full Wind invasion, food stagnation, retained pathogens). Use cautiously where Damp accumulation is prominent — many Qi tonics are sweet and can be cloying. Avoid combining with simultaneous strong pathogen-clearing without the practitioner balancing the formula.

Modern drug interactions

Significant interactions: Glycyrrhizin inhibits the renal enzyme 11β-HSD2, causing pseudoaldosteronism with prolonged or high-dose use — oedema, hypertension and hypokalaemia. Increases the risk of digoxin toxicity, potentiates corticosteroid effects (including topical, inhaled and systemic), interacts with potassium-wasting diuretics (loop and thiazide), ACE inhibitors and antihypertensives. Avoid in patients with hypertension, oedema, heart failure, hypokalaemia and chronic kidney disease. Honey-fried Zhi Gan Cao at standard dose for short to medium courses is generally safe; raw Gan Cao at high dose is the form most associated with adverse effects.

Important: Chinese herbs should always be prescribed by a fully qualified herbalist who is a member of the Register of Chinese Herbal Medicine (RCHM). Never self-prescribe or self-administer Chinese herbs without professional guidance. Dr (TCM) Attilio D’Alberto is a member of the RCHM and the British Acupuncture Council with over 25 years of clinical experience.

8. Treatment at my clinic

I prescribe Gān Cǎo as part of tailored herbal formulas for a range of conditions including Burnout, Chronic fatigue syndrome, Digestive disorders. Every prescription is individually formulated following a full TCM assessment and adjusted throughout treatment as the pattern responds.

I see patients in person at my clinic in Wokingham, Berkshire. Online Chinese herbal medicine consultations are available for patients throughout the UK and internationally, with herbs dispensed by post. Visit the prices page for consultation fees.

Return to the Chinese herb directory or the Chinese herbal medicine main page.

Prefer to be treated from home? Chinese herbal medicine online consultations are available throughout the UK and worldwide. After a full video consultation, Dr (TCM) Attilio D'Alberto formulates a bespoke herbal prescription and posts your Chinese herbs directly to your door.