Licorice Root

© Steven Foster

This fact sheet provides basic information about licorice root—common 

names, what the science says, potential side effects and cautions, and 

resources for more information.

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

zao (Chinese licorice)

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

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. Today, licorice is used as a folk or traditional remedy for 

stomach ulcers, bronchitis, and sore throat, as well as infections caused 

by viruses, such as hepatitis.

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 

• An injectable form of licorice extract—not available in the United 

States—has been shown to have beneficial effects against hepatitis 

C in clinical trials. There are no reliable data on oral forms of 

licorice for hepatitis C. More research is needed before reaching 

any conclusions.

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

effective for any condition.

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 dietary supplement for more than 4

to 6 weeks has not been thoroughly studied. 
• Taking licorice together with diuretics (water pills), corticosteroids, 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 all your health care providers about any complementary health practices you use. Give 

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

coordinated and safe care. For tips about talking with your health care providers about 

complementary and alternative medicine, see NCCAM’s Time to Talk campaign at 

nccam.nih.gov/timetotalk/. 

Sources

Armanini D, Fiore C, Bielenberg J. 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 www.naturaldatabase.com on July 15, 2009.

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

www.naturalstandard.com on July 15, 2009.

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

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

National Center for Complementary and Alternative Medicine. CAM and Hepatitis C: A Focus on Herbal Supplements. National 

Center for Complementary and Alternative Medicine Web site. Accessed at 

nccam.nih.gov/health/hepatitisc/hepatitiscfacts.htm on June 3, 2010.

For More Information

Visit the NCCAM Web site at nccam.nih.gov and view Using Dietary Supplements Wisely

(nccam.nih.gov/health/supplements/wiseuse.htm).

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

PubMed®

Web site: www.ncbi.nlm.nih.gov/sites/entrez

NIH Office of Dietary Supplements

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

NIH National Library of Medicine’s MedlinePlus

Licorice Listing: www.nlm.nih.gov/medlineplus/druginfo/natural/881.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

D318

Created June 2006

Updated April 2012