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.
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.
Source: Herbs at a Glance. https://nccih.nih.gov/health/licoriceroot.