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Licorice Root 

This fact sheet provides basic information about licorice root—common names, 

uses, potential side effects, and resources for more information. Most licorice is 

grown in Greece, Turkey, and Asia. Licorice contains a compound called 

glycyrrhizin (or glycyrrhizic acid). Licorice has a long history of medicinal use in 

both Eastern and Western systems of medicine. 

Common Names—licorice root, licorice, liquorice, sweet root, gan zao 

(Chinese licorice) 

Latin Names—Glycyrrhiza glabra, Glycyrrhiza uralensis (Chinese licorice) 

What It Is Used For 

Licorice root has been used as a dietary supplement for stomach ulcers, bronchitis, 

and sore throat, as well as infections caused by viruses, such as hepatitis. 

How It Is Used 

•	 Peeled licorice root is available in dried and powdered forms. 

•	 Licorice root is available as capsules, tablets, and liquid extracts. 

•	 Licorice can be found with glycyrrhizin removed; the product is called DGL 

(for “deglycyrrhizinated licorice”). 

What the Science Says 

•	 A review of several clinical trials found that glycyrrhizin might reduce 

complications from hepatitis C in some patients. However, there is not 

enough evidence to confirm that glycyrrhizin has this effect. 

•	 There are not enough reliable data to determine whether licorice is effective 

for stomach ulcers. 

Side Effects and Cautions 

•	 In large amounts, licorice containing glycyrrhizin can cause high blood pressure, 

salt and water retention, and low potassium levels, which could lead to heart 

problems. DGL products are thought to cause fewer side effects. 

•	 The safety of using licorice as a supplement for more than 4 to 6 weeks has 

not been thoroughly studied. 

•	 Taking licorice together with diuretics (water pills) or other medicines that reduce 

the body’s potassium levels could cause dangerously low potassium levels. 

•	 People with heart disease or high blood pressure should be cautious about 

using licorice. 
 

 

•	 When taken in large amounts, licorice can affect the body’s levels of a hormone called 

cortisol and related steroid drugs, such as prednisone. 

•	 Pregnant women should avoid using licorice as a supplement or consuming large amounts 

of licorice as food, as some research suggests it could increase the risk of preterm labor. 

•	 Tell your health care providers about any complementary and alternative practices you 

use. Give them a full picture of what you do to manage your health. This will help ensure 

coordinated and safe care. 

Sources 

National Center for Complementary and Alternative Medicine. Hepatitis C and Complementary and Alternative Medicine: 

2003 Update. National Center for Complementary and Alternative Medicine Web site. Accessed at 

http://nccam.nih.gov/health/hepatitisc on July 12, 2007. 

Licorice (Glycyrrhiza glabra). In: Coates P, Blackman M, Cragg G, et al., eds. Encyclopedia of Dietary Supplements. New York, 

NY: Marcel Dekker; 2005:391-399. 

Licorice. Natural Medicines Comprehensive Database Web site. Accessed at http://www.naturaldatabase.com on 

July 12, 2007. 

Licorice (Glycyrrhiza glabra L.) and DGL (deglycyrrhizinated licorice). Natural Standard Database Web site. Accessed at 

http://www.naturalstandard.com on July 12, 2007. 

Licorice root. In: Blumenthal M, Goldberg A, Brinckman J, eds. Herbal Medicine: Expanded Commission E Monographs. 

Newton, MA: Lippincott Williams & Wilkins; 2000:233-239. 

For More Information 

Visit the NCCAM Web site at nccam.nih.gov and view: 

•	 What’s in the Bottle? An Introduction to Dietary Supplements at nccam.nih.gov/health/bottle/ 

•	 Herbal Supplements: Consider Safety, Too at nccam.nih.gov/health/supplement-safety/ 

NCCAM Clearinghouse 

Toll-free in the U.S.: 1-888-644-6226 

TTY (for deaf and hard-of-hearing callers): 1-866-464-3615 

E-mail: info@nccam.nih.gov 

CAM on PubMed 

Web site: nccam.nih.gov/camonpubmed/ 

NIH Office of Dietary Supplements 

Web site: www.ods.od.nih.gov 

NIH National Library of Medicine’s MedlinePlus 

Licorice Root Listing: www.nlm.nih.gov/medlineplus/druginfo/natural/patient-licorice.html 

This publication is not copyrighted and is in the public domain. Duplication is encouraged. 

NCCAM has provided this material for your information. It is not intended to substitute for 

the medical expertise and advice of your primary health care provider. We encourage you to 

discuss any decisions about treatment or care with your health care provider. The mention of 

any product, service, or therapy is not an endorsement by NCCAM. 

National Institutes of Health 

♦♦♦

U.S. Department of Health and Human Services 

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Created June 2006 

Updated June 2008 

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