Common Names: licorice root, licorice, liquorice, sweet root, gan cao, gan-zao, Chinese licorice
Latin Names: Glycyrrhiza glabra, Glycyrrhiza uralensis
- Most licorice root grows in Greece, Turkey, and Asia. Anise oil is often used instead of licorice root to flavor licorice candy.
- Centuries ago, licorice root was used in Greece, China, and Egypt for stomach inflammation and upper respiratory problems. Licorice root also has been used as a sweetener.
- Today, people use licorice root as a dietary supplement for digestive problems, menopausal symptoms, cough, and bacterial and viral infections. People also use it as a shampoo.
- Licorice is harvested from the plants’ roots and underground stems. Licorice supplements are available as capsules, tablets, and liquid extracts.
How Much Do We Know?
- A number of studies of licorice root in people have been published, but not enough to support the use for any specific health condition.
What Have We Learned?
- Glycyrrhizin—a compound found in licorice root—has been tested in a few clinical trials in hepatitis C patients, but there’s currently not enough evidence to determine if it’s helpful. Laboratory studies done in Japan (where an injectable glycyrrhizin compound is used in people with chronic hepatitis C who do not respond to conventional treatment) suggest that glycyrrhizin may have some effect against hepatitis C.
- There’s some evidence that topical licorice extract may improve skin rash symptoms, such as redness, swelling, and itching.
- A Finnish study of mothers and their young children suggested that eating a lot of actual licorice root during pregnancy may harm a child’s developing brain, leading to reasoning and behavioral issues, such as attention problems, rule-breaking, and aggression.
- Studies of licorice root extracts in people for cavities, mouth ulcers, and oral yeast infections have returned mixed results.
What Do We Know About Safety?
- In large amounts and with long-term use, licorice root can cause high blood pressure and low potassium levels, which could lead to heart and muscle problems. Some side effects are thought to be due to a chemical called glycyrrhizic acid. Licorice that has had this chemical removed (called DGL for deglycyrrhizinated licorice) may not have the same degree of side effects.
- Taking licorice root containing glycyrrhizinic acid with medications that reduce potassium levels such as diuretics might be bad for your heart.
- Pregnant women should avoid using licorice root as a supplement or consuming large amounts of it as food.
Keep in Mind
- Tell all your health care providers about any complementary or integrative health approaches you use. Give them a full picture of what you do to manage your health. This will help ensure coordinated and safe care.
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- Dhiman RK, Chawla YK. Herbal medicines for liver diseases. Digestive Diseases and Sciences. 2005;50(10):1807-1812.
- Jalili J, Askeroglu U, Alleyne B, et al. Herbal products that may contribute to hypertension. Plastic and Reconstructive Surgery. 2013;131(1):168-173.
- Licorice. Natural Medicines Web site. Accessed at naturalmedicines.therapeuticresearch.com on April 8, 2015. [Database subscription]
- Matsumoto Y, Matsuura T, Aoyagi H, et al. Antiviral activity of glycyrrhizin against hepatitis C virus in vitro. PLoS One. 2013;8(7):e68992.
- Messier C, Epifano F, Genovese S, et al. Licorice and its potential beneficial effects in common oro-dental diseases. Oral Diseases. 2012;18(1):32-39.
- Räikkönen K, Pesonen A-K, Heinonen K, et al. Maternal licorice consumption and detrimental cognitive and psychiatric outcomes in children. American Journal of Epidemiology. 2009;170(9):1137-1146.
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