Is Liquorice Inflammatory? Unpacking the Science

November 23, 2025 •

4 min read

For thousands of years, liquorice has been used in traditional medicine for its various benefits. But is liquorice inflammatory or does it help fight inflammation? The root of the Glycyrrhiza glabra plant contains powerful anti-inflammatory compounds, challenging common misconceptions.

Quick Summary

Liquorice contains active compounds like glycyrrhizin that possess strong anti-inflammatory properties, inhibiting cytokines and enzymes that drive inflammation. However, excessive intake can cause adverse side effects like high blood pressure, separate from inflammation.

Key Points

Anti-inflammatory Properties: Liquorice root contains potent anti-inflammatory compounds like glycyrrhizin and flavonoids.
Mechanism of Action: It works by inhibiting pro-inflammatory pathways like NF-κB and key enzymes such as COX-2.
Potential Side Effects: Excessive consumption of glycyrrhizin can cause side effects like high blood pressure and low potassium due to its mineralocorticoid-like activity.
Safe Alternatives: Deglycyrrhizinated licorice (DGL) is an option that retains many benefits but removes the glycyrrhizin, minimizing systemic side effects.
Supports Various Conditions: Research indicates liquorice may help with inflammatory conditions of the GI tract, respiratory system, and skin.

The Anti-Inflammatory Power of Liquorice

Contrary to being inflammatory, extensive research shows that liquorice, particularly its root (Glycyrrhiza glabra), possesses significant anti-inflammatory properties. This therapeutic effect is primarily attributed to several bioactive compounds found in the plant, with the triterpenoid saponin glycyrrhizin (or glycyrrhizic acid) being the most well-known. Glycyrrhizin, along with various flavonoids and other phenolic compounds, is responsible for modulating the body's inflammatory response in a beneficial way.

How Liquorice Compounds Inhibit Inflammation

The anti-inflammatory mechanisms of liquorice are complex and act on multiple molecular pathways in the body. The primary active component, glycyrrhizin, works through several key actions:

Inhibiting Inflammatory Pathways: Glycyrrhizin blocks the activation of the nuclear factor-kappa B (NF-κB) pathway. Since NF-κB controls the expression of numerous pro-inflammatory genes, its inhibition prevents the production of cytokines and other inflammatory mediators.
Suppressing Pro-inflammatory Cytokines: Compounds in liquorice have been shown to decrease the levels of inflammatory cytokines, such as tumor necrosis factor-alpha (TNF-α), interleukin-1β (IL-1β), and interleukin-6 (IL-6). These cytokines are key drivers of both acute and chronic inflammation.
Blocking Enzymes: Liquorice extracts can inhibit the activity of enzymes like cyclooxygenase-2 (COX-2) and inducible nitric oxide synthase (iNOS), which are responsible for producing prostaglandins and nitric oxide, both significant mediators of inflammation.
Modulating Cortisol: Glycyrrhetinic acid, a metabolite of glycyrrhizin, inhibits the enzyme 11β-hydroxysteroid dehydrogenase type 2 (11β-HSD2). This inhibition leads to increased levels of cortisol, a natural anti-inflammatory hormone, in certain tissues.
Antioxidant Effects: By scavenging free radicals, liquorice compounds also help reduce oxidative stress, a process closely linked to inflammation and cellular damage.

Clinical Applications of Liquorice for Inflammation

Thanks to its multifaceted anti-inflammatory actions, liquorice has been studied for its potential use in a variety of inflammatory conditions. Some of the most notable applications include:

Gastrointestinal Disorders: Liquorice is widely used to treat stomach ulcers, gastritis, and acid reflux due to its ability to reduce inflammation and promote mucus production in the gastrointestinal lining. Deglycyrrhizinated licorice (DGL) is often used for this purpose to avoid systemic side effects.
Respiratory Conditions: Traditional and modern uses include treating coughs, bronchitis, and asthma, with some research suggesting that glycyrrhizin can help ease symptoms due to its anti-inflammatory effects on the airways. A clinical trial even found that a liquorice gargle was effective at reducing post-operative sore throat.
Skin Conditions: Topical applications of liquorice extract have shown promise in treating inflammatory skin conditions like eczema and acne, reducing redness, swelling, and irritation. Its brightening properties are also valued in dermocosmetics.
Chronic Diseases: Preclinical studies have explored the potential of liquorice compounds in modulating inflammation in chronic diseases such as arthritis, hepatitis, and inflammatory bowel diseases, though more clinical evidence is needed.

The Critical Distinction: Anti-Inflammatory Effects vs. Adverse Effects

While liquorice is proven to be anti-inflammatory, its key compound, glycyrrhizin, can cause adverse side effects if consumed in excessive quantities for prolonged periods. This is a crucial point of distinction. These side effects are related to its mineralocorticoid-like activity, not its anti-inflammatory properties.

Excessive glycyrrhizin consumption can lead to pseudo-hyperaldosteronism, a condition that mimics the effects of having too much aldosterone. This leads to:

High Blood Pressure (Hypertension): The body retains sodium and water, which increases blood pressure.
Low Potassium Levels (Hypokalemia): The body loses potassium, which can lead to fatigue, muscle cramps, and heart rhythm problems.
Fluid Retention (Edema): The retention of sodium and water results in swelling.

To avoid these side effects, many commercial products, especially those aimed at digestive health, use Deglycyrrhizinated Licorice (DGL), which removes the glycyrrhizin compound.

Comparison of Regular Liquorice and DGL


Feature	Regular Liquorice Extract	Deglycyrrhizinated Licorice (DGL)
Active Compounds	Contains glycyrrhizin, flavonoids, and other compounds.	Glycyrrhizin is removed, contains beneficial flavonoids and other compounds.
Primary Anti-Inflammatory Agent	Glycyrrhizin, though flavonoids also play a role.	Flavonoids are the primary anti-inflammatory agents.
Risk of Side Effects	High risk of hypertension, hypokalemia, and fluid retention with excessive, chronic use.	Very low risk of high blood pressure or potassium imbalances.
Best for	Short-term use or in controlled medical settings to leverage glycyrrhizin's potency.	Long-term use, especially for digestive issues like ulcers and reflux, to avoid systemic side effects.
Mechanism	Inhibits NF-κB, COX-2, and increases cortisol effects.	Focuses on inhibiting inflammatory enzymes and scavenging radicals.

Conclusion

In conclusion, liquorice is not inflammatory; its primary compounds are demonstrably anti-inflammatory and have been used for centuries to treat various inflammatory conditions. It achieves this by modulating key signaling pathways, inhibiting pro-inflammatory enzymes, and providing antioxidant support. However, it is crucial to differentiate its anti-inflammatory effects from the well-documented adverse side effects associated with excessive, long-term consumption of its glycyrrhizin content. For regular or high-dose use, particularly for digestive health, deglycyrrhizinated licorice (DGL) offers a safer alternative by removing the component responsible for systemic side effects. Always exercise caution and moderation, especially if you have pre-existing health conditions or take other medications.

For more in-depth scientific research on the topic, consult studies published in reputable journals, such as this review on the anti-inflammatory properties of licorice in intestinal disorders.

Frequently Asked Questions

Yes, liquorice root is generally considered anti-inflammatory. It contains compounds like glycyrrhizin and various flavonoids that have been shown to reduce inflammation by inhibiting key pathways and reducing pro-inflammatory cytokines.

Liquorice fights inflammation through several mechanisms, including suppressing the NF-κB signaling pathway, inhibiting enzymes like COX-2, and reducing the levels of pro-inflammatory cytokines like TNF-α and IL-6.

Yes, excessive consumption of regular black liquorice candy can raise blood pressure. This is because its active compound, glycyrrhizin, can cause the body to retain sodium and excrete potassium, mimicking the effect of excess aldosterone.

DGL stands for deglycyrrhizinated liquorice. It is a form of liquorice extract with the glycyrrhizin compound removed. This makes it safer for long-term use, especially for digestive issues, as it does not cause the blood pressure and potassium side effects associated with regular liquorice.

No, liquorice is not safe for everyone. People with pre-existing conditions like hypertension, heart disease, or kidney problems should avoid excessive intake of products containing glycyrrhizin. Pregnant or nursing women should also exercise caution and consult a doctor.

Yes, topical applications of liquorice extract are often used to help with inflammatory skin conditions. Its anti-inflammatory and antioxidant properties can reduce redness, irritation, and soothe the skin.

The U.S. FDA advises that consuming more than 2 ounces of black liquorice a day for two weeks could be problematic for people over 40. However, individuals vary in sensitivity, and some experts suggest a daily intake of no more than 100 mg of glycyrrhizin.