Licorice root supplements are promoted for aiding digestion, respiratory issues, and menopausal symptoms. Traditionally, this herb has been used to treat asthma, lung diseases, and for wound healing.
However, licorice root contains glycyrrhizin, a compound that can interact with certain medications and elevate blood pressure. People with high blood pressure or heart rhythm irregularities should avoid it.
Some individuals use licorice root to treat peptic ulcers, inflammation, gastrointestinal disorders, and hepatitis. Certain licorice products may also provide benefits for those with canker sores, bad breath, or atopic dermatitis (eczema).
Two randomized controlled trials suggest that licorice root might help with nonalcoholic fatty liver disease and wound healing.
However, current research is limited. There isn't enough high-quality evidence to support the claimed benefits of licorice root for digestion, respiration, inflammation, antiviral properties, or antimicrobial effects, according to Ericka Ridgeway, PharmD, director of pharmacy at Henry Ford Health in Detroit.
A recent study found that a daily dose of 100 mg of glycyrrhizic acid—considered safe by the World Health Organization—may still cause an increase in blood pressure.
Glycyrrhizin can lead to sodium retention, fluid buildup, and potassium loss, which result in higher blood pressure. Glycyrrhizin mimics the hormone aldosterone, which balances sodium and potassium levels. Excess aldosterone and glycyrrhizin can cause fluid retention and increased blood pressure.
Glycyrrhizin may interact with some medications like diuretics, insulin, anticoagulants, and blood pressure drugs such as spironolactone (aldactone).
"Many people believe herbal means harmless, but licorice root demonstrates a plant with powerful pharmacological effects," said Iman Majd, MD, LAc, an associate professor of family medicine at UW Medicine's Osher Center for Integrative Health.
Majd mentioned that even healthy individuals may experience side effects from licorice root, and vulnerable groups could face severe complications. Some products remove glycyrrhizin to minimize harmful side effects.
"Avoid supplements, teas, or candies listing 'licorice root' or 'glycyrrhiza' unless they are confirmed de-glycyrrhizinated (DGL)," Majd advised.
Licorice candies or teas containing glycyrrhizin can have similar side effects to licorice supplements. A 2019 case report indicated that consuming excessive amounts of black licorice candy could cause low potassium levels and severe heart problems.
However, not all licorice confections need to be avoided if you enjoy the taste. "Many commercial 'licorice' candies in the U.S. are flavored with anise rather than real licorice and thus don't carry the same health risks," Majd noted.
Natural products, herbal teas, and some imported candies may contain high levels of glycyrrhizin, so it's crucial to check labels for hidden glycyrrhizin, advised Majd. Other herbs can offer similar benefits to licorice root.
"Ginger is an excellent option for digestive support, while slippery elm or marshmallow root can help soothe the throat and airways," said Melissa Mroz-Planells, DCN, RDN, a registered dietitian based in Seattle. Always consult with a healthcare provider before starting any supplements, particularly if you have health conditions or are taking other medications.
Licorice root can boost blood pressure and interact dangerously with some medications. Even small amounts of glycyrrhizin may cause side effects, especially for those with heart or kidney problems. Always check product labels carefully and consider using deglycyrrhizinated (DGL) options or alternative herbs like ginger for similar benefits.