Herbal Fact Sheet: Licorice Root

Background

• 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.