Liquorice root tea is a caffeine-free herbal infusion brewed from the dried root of Glycyrrhiza glabra (European liquorice) or G. uralensis (Chinese liquorice, 甘草 gāncǎo), producing a brew that is naturally 30–50 times sweeter than sucrose due to its glycyrrhizin content. The characteristic anise-like sweetness, anti-inflammatory properties, and soothing effect on mucous membranes have made liquorice root one of the world’s most widely used medicinal plants — while its potent bioactive compound glycyrrhizin also means that excessive consumption carries real and documented health risks.
In-Depth Explanation
The plant:
Glycyrrhiza glabra (European liquorice) is grown across the Mediterranean, the Middle East, and Central Asia. G. uralensis is the Chinese pharmacopoeial species, among the most frequently used herbs in Traditional Chinese Medicine. The root and stolons (underground stems) are harvested after 3–5 years, dried, and used either whole, sliced, or extracted.
The key compound — glycyrrhizin:
The defining compound of liquorice is glycyrrhizin (also called glycyrrhizinic acid), accounting for 2–25% of dry root weight. Its properties include:
- Sweetness: ~30–50× sucrose by weight; does not spike blood glucose like sugar
- Anti-inflammatory: Inhibits prostaglandin and leukotriene synthesis; similar to mild cortisol activity
- Antiviral: Shown to inhibit numerous viruses including influenza, hepatitis C, and SARS coronavirus in vitro
- Adrenal effects: Inhibits 11β-hydroxysteroid dehydrogenase, effectively extending the biological activity of cortisol — this is the source of both its therapeutic use (adrenal fatigue support in naturopathy) and its safety concerns
Safety considerations:
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⚠️ Excessive liquorice root consumption is genuinely hazardous.
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Glycyrrhizin’s cortisol-mimicking effect, when consumed in large quantities over time, causes:
- Pseudohyperaldosteronism: Sodium retention, potassium loss
- Hypertension (elevated blood pressure): Documented in many case reports
- Oedema (swelling) and hypokalaemia (low potassium)
- Cardiac arrhythmias in severe cases
The FDA, EFSA, and most national health authorities recommend limiting whole liquorice root consumption. The threshold associated with adverse effects in clinical literature is approximately 100mg glycyrrhizin/day over extended periods — roughly equivalent to 30–50g whole dried root or more.
DGL (Deglycyrrhizinated Liquorice) is a processed form with glycyrrhizin removed, used for digestive applications (gastric ulcer support) without the blood pressure risk.
Traditional uses:
| System | Use | Evidence assessment |
|---|---|---|
| TCM | Harmonising herb (调和诸药); cough; gastric complaints | Extensive traditional use; significant pharmacological research |
| Ayurveda | Yashtimadhu; respiratory, digestive, immunomodulatory | Traditional use; limited RCT evidence |
| European phytotherapy | Throat soother; gastric ulcer (DGL); adrenal support | Good evidence for gastric use; throat use well-supported |
History
Liquorice is one of the oldest documented medicinal plants. Egyptian papyri record it as a remedy for coughs and gastric complaints; it was found in Tutankhamun’s tomb. Greek physician Theophrastus documented Glycyrrhiza (from Greek glykys “sweet” + rhiza “root”) in the 3rd century BCE. In Chinese medicine, 甘草 (gāncǎo) has been continuously documented for over 2,000 years as one of the most important harmonising herbs in formulae, used in the majority of TCM prescriptions in some form.
The European liquorice confectionery tradition (liquorice candy, Pontefract cakes, Dutch drop) developed separately from the medicinal tradition and eventually eclipsed it in popular consciousness.
Common Misconceptions
“Liquorice flavouring in candy comes from liquorice root.” Most modern liquorice-flavoured confectionery uses anise oil or artificial flavourings, not actual liquorice root. The distinctive flavour of real liquorice root is similar but distinct from anise — sweeter and more complex.
“Liquorice tea is totally safe because it is herbal.” This is the most important misconception to address. Liquorice root has genuine drug-like interactions and dose-dependent risks. Short-term, moderate use (1–2 cups/day, a few weeks) is generally safe for healthy adults. Daily use over months, or heavy use, can raise blood pressure significantly. People with hypertension, kidney disease, or on corticosteroids should avoid it.
Taste Profile & How to Identify
Aroma: Sweet anise, slightly woody, warm.
Flavour: Intensely sweet, anise-like, smooth, lingering.
Colour: Amber to light brown.
Mouthfeel: Medium body, slightly viscous, sweet coating.
Brewing Guide
| Parameter | Value |
|---|---|
| Amount | 1–3 slices dried root or 1 tsp cut root per 250ml |
| Water temperature | 100°C |
| Steep time | 5–10 minutes (or simmer 5 min for stronger extraction) |
| Infusions | 2 |
No sweetener needed — glycyrrhizin provides intense sweetness. Often blended with mint, ginger, or chamomile to balance. A small piece of root in a herbal blend sweetens the whole cup without sucrose.
Last updated: 2026-04
Related Terms
See Also
Research
- Asl, M.N., & Hosseinzadeh, H. (2008). Review of pharmacological effects of Glycyrrhiza sp. and its bioactive compounds. Phytotherapy Research, 22(6), 709–724.
[Comprehensive review of glycyrrhizin and related triterpenoids: anti-inflammatory, antiviral, endocrine effects and clinical safety data.]
- Stormer, F.C., et al. (1993). Glycyrrhizinic acid in liquorice — evaluation of health hazard. Food and Chemical Toxicology, 31(4), 303–312.
[Foundational safety evaluation of glycyrrhizin intake, establishing dose thresholds associated with pseudohyperaldosteronism and hypertension risk.]