Tuesday, August 10, 2010

Licorice Root

Licorice Root

Keywords: sweet root, gan zao, chinese licorice, Hepatitis C

Licorice Root
© Steven Foster

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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 NamesGlycyrrhiza glabra, Glycyrrhiza uralensis (Chinese licorice)

What Licorice Root 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 Licorice Root 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

  • 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 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 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. For tips about talking with your health care providers about CAM, see NCCAM's Time to Talk campaign.


  • Licorice. Natural Medicines Comprehensive Database Web site. Accessed at www.naturaldatabase.com on July 15, 2009.
  • 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 (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 on June 3, 2010.

For More Information

NCCAM Clearinghouse

The NCCAM Clearinghouse provides information on CAM and NCCAM, including publications and searches of Federal databases of scientific and medical literature. The Clearinghouse does not provide medical advice, treatment recommendations, or referrals to practitioners.
Toll-free in the U.S.: 1-888-644-6226
TTY (for deaf and hard-of-hearing callers): 1-866-464-3615
Web site: nccam.nih.gov
E-mail: info@nccam.nih.gov

CAM on PubMed®

NIH Office of Dietary Supplements

Web site: www.ods.od.nih.gov

NIH National Library of Medicine's MedlinePlus

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.
NCCAM Publication No. D318
Created June 2006
Updated July 2010
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