Licorice Root

Medically reviewed by Prof. Giorgi Pkhakadze, MD, MPH, PhD — GMJ Editorial Board

Scientific name: Glycyrrhiza glabra
Category: Herbal compound/nutraceutical
RDA: Not established
UL: Not established

What is Licorice Root?

Licorice root comes from the Glycyrrhiza glabra plant, a perennial herb native to Europe and Asia. The root has been used for thousands of years in traditional medicine systems, particularly in Chinese and Ayurvedic practices. The primary bioactive compound responsible for licorice’s therapeutic effects is glycyrrhizin, which can comprise 2-15% of the root’s dry weight. Deglycyrrhizinated licorice (DGL) is a processed form where glycyrrhizin has been removed to reduce potential side effects while preserving other beneficial compounds like flavonoids and saponins.

Licorice root is available as whole root, powder, extracts, and standardized supplements. The characteristic sweet taste, approximately 50 times sweeter than sugar, comes from glycyrrhizin and has made licorice popular in confectionery, though most commercial licorice candy today uses anise flavoring instead.

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Health benefits & uses

Digestive health (Moderate evidence): Studies suggest DGL may help protect the stomach lining and support healing of peptic ulcers. A systematic review found that licorice-containing preparations showed comparable effectiveness to conventional treatments for functional dyspepsia.

Upper respiratory support (Moderate evidence): Licorice root has demonstrated anti-inflammatory and antimicrobial properties that may benefit respiratory health. Clinical trials indicate potential benefits for cough reduction and throat irritation relief.

Skin conditions (Limited evidence): Topical licorice preparations containing glycyrrhetinic acid have shown promise for inflammatory skin conditions like eczema and dermatitis in small studies, though more research is needed.

Liver health (Limited evidence): Some studies suggest licorice may support liver function and help with certain liver conditions, but evidence remains preliminary and requires further investigation.

Menopausal symptoms (Limited evidence): Early research indicates licorice root may help reduce hot flashes and other menopausal symptoms, though larger, well-controlled studies are needed.

How it works

Licorice root contains over 300 chemical compounds, with glycyrrhizin being the most studied. Glycyrrhizin is metabolized to glycyrrhetinic acid, which has anti-inflammatory, antimicrobial, and antiviral properties. This compound can inhibit 11β-hydroxysteroid dehydrogenase, an enzyme that converts cortisol to its inactive form, potentially leading to mineralocorticoid effects.

Other bioactive compounds include flavonoids like liquiritigenin and isoliquiritigenin, which contribute to antioxidant and anti-inflammatory activities. The polysaccharides in licorice root may support immune function, while triterpene saponins contribute to the herb’s expectorant properties.

Dosage

Typical adult dosage ranges vary significantly based on the form and intended use:

• Standardized extract: 200-800 mg daily
• DGL: 380-1,140 mg taken 20 minutes before meals
• Dried root: 1-5 grams daily as tea
• Liquid extract: 2-4 ml three times daily

For glycyrrhizin-containing products, intake should generally not exceed 100 mg of glycyrrhizin daily for extended periods. Treatment duration should typically be limited to 4-6 weeks unless under professional supervision. Always consult with a healthcare provider before starting supplementation, especially for therapeutic uses.

Food sources

Licorice root is not commonly found in everyday foods. Natural sources include:

• Licorice root tea (dried root)
• Traditional herbal preparations
• Some authentic European licorice candies (though most commercial varieties use artificial flavoring)
• Certain traditional Middle Eastern and Asian dishes
• Some herbal medicine formulations

Most people obtain licorice root through supplements rather than food sources, as therapeutic amounts are difficult to achieve through dietary intake alone.

Safety & side effects

Short-term use of licorice root is generally well-tolerated by most adults. However, prolonged use or high doses, particularly of glycyrrhizin-containing forms, can cause significant side effects including:

• High blood pressure
• Low potassium levels (hypokalemia)
• Fluid retention and swelling
• Headaches
• Muscle weakness
• Heart rhythm abnormalities

These effects are primarily due to glycyrrhizin’s impact on mineralocorticoid activity. DGL forms have fewer of these concerns but should still be used cautiously.

Interactions

Medications: Licorice can interact with numerous medications including blood pressure medications, diuretics, insulin, blood thinners, and corticosteroids. It may potentiate the effects of digoxin and increase the risk of dangerous heart rhythm changes.

Other supplements: May interact with other herbs that affect blood pressure or blood sugar. Concurrent use with other potassium-depleting supplements should be avoided.

Laboratory tests: May affect cortisol and aldosterone measurements, potentially interfering with certain medical tests.

Who should be cautious

Certain individuals should avoid or use licorice root only under medical supervision:

• People with high blood pressure, heart disease, or kidney disease
• Individuals with hormone-sensitive conditions
• Those with diabetes (may affect blood sugar)
• Pregnant and breastfeeding women
• People taking blood pressure medications or diuretics
• Those with liver disease
• Anyone scheduled for surgery (should discontinue 2 weeks prior)

Frequently asked questions

Is DGL safer than regular licorice root?

Yes, deglycyrrhizinated licorice (DGL) has had the glycyrrhizin removed, which eliminates most of the blood pressure and electrolyte-related side effects. DGL is generally considered safer for long-term use while still providing many of the digestive benefits.

Can licorice root help with weight loss?

Some small studies suggest licorice root may influence body composition and reduce abdominal fat, but evidence is very limited. It should not be relied upon as a weight loss aid, and any potential benefits must be weighed against safety concerns.

How long can I safely take licorice root supplements?

For glycyrrhizin-containing forms, most experts recommend limiting use to 4-6 weeks. DGL may be used for longer periods but should still be monitored by a healthcare provider, especially if used daily for extended periods.

Does licorice candy provide the same benefits?

Most commercial licorice candy contains little to no actual licorice root, using anise flavoring instead. Even authentic licorice candy contains much lower concentrations of active compounds compared to supplements.

Can licorice root affect hormone levels?

Yes, licorice root can affect various hormones including cortisol, aldosterone, and potentially sex hormones. This is why people with hormone-sensitive conditions should be particularly cautious and consult healthcare providers before use.