Best studied for: Peptic ulcer and gastric mucosal protection; Upper respiratory soothing and cough; GERD and functional dyspepsia.
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What is Licorice Root? Licorice root is derived from the root and rhizome of Glycyrrhiza glabra (European/Spanish licorice) and Glycyrrhiza uralensis (Chinese licorice), perennial leguminous plants native to southern Europe, the Middle East, and central and western Asia. The root contains glycyrrhizin at concentrations typically ranging from 2–25% , which is 30–50 times sweeter than sucrose and responsible for both its characteristic flavor and many of its pharmacological effects. Deglycyrrhizinated licorice (DGL) is a processed form from which most of the glycyrrhizin has been removed, retaining the flavonoid-rich fraction while substantially reducing the risk of mineralocorticoid side effects. How does Licorice Root work? Glycyrrhizin is metabolized in the gut to 18β-glycyrrhetinic acid, which inhibits the enzyme 11β-hydroxysteroid dehydrogenase type 2 (11β-HSD2), thereby preventing the local inactivation of cortisol to cortisone and producing aldosterone-like effects on sodium and potassium balance. The flavonoid fraction—including glabridin, liquiritin, and licochalcone A—exerts anti-inflammatory effects by inhibiting NF-κB signaling, COX-2 activity, and reactive oxygen species generation in mucosal and immune cells. In the gastrointestinal tract, DGL compounds appear to stimulate mucus secretion, promote prostaglandin synthesis in the gastric mucosa, and support epithelial integrity, contributing to ulcer healing independent of glycyrrhizin. What forms does Licorice Root come in? DGL chewable tablets (typically 380–760 mg per tablet, chewed before meals) are the most studied and safest form for peptic ulcer disease and GERD because the chewing process activates salivary compounds that may enhance mucosal effects. Standardized whole-root extracts are used for adrenal support, respiratory conditions, and anti-inflammatory applications but should be dose-limited and cycled. Tinctures (1:5 hydroethanolic) provide flexible dosing. Topical preparations containing 2% licorice extract have been evaluated in dermatology for hyperpigmentation and eczema. Where it comes from: Licorice root has been used medicinally for over 4,000 years , appearing in the Egyptian Ebers Papyrus and in traditional Chinese medicine (TCM) as Gan Cao, the most frequently prescribed herb in TCM formulas as a harmonizing agent. Greek physician Theophrastus documented its use for thirst and respiratory complaints around 300 BCE. Western herbalism later adopted it as a primary remedy for peptic ulcer disease, and by the mid-20th century carbenoxolone—a semisynthetic derivative of glycyrrhetinic acid—was an approved pharmaceutical treatment for peptic ulcers in several countries.
Helps
What does Licorice Root help with? Licorice root is the dried root of a plant. Two kinds are used: Glycyrrhiza glabra and Glycyrrhiza uralensis. It holds a strong compound called glycyrrhizin, plus many plant flavonoids. Mouth sores caused by chemotherapy Good evidence — two randomised human trials with placebo rinses, one with 60 people. In a trial of 60 people on chemo, a 0.5% licorice mouthwash beat a placebo rinse. Sores were less severe and pain scores fell (Asl et al., 2012, Daru). A second trial found shorter, milder sores (Araghchian et al., 2017, Journal of Herbal Medicine). Evidence grade B · Traditional tier T3 Stomach and gut ulcers Good evidence — controlled human trials of DGL tablets, plus older drug trials. DGL is licorice with the glycyrrhizin taken out. In controlled trials, DGL tablets healed stomach and duodenal ulcers more often than placebo (Turpie et al., 1969, British Medical Journal; Morgan et al., 1982, Gut). Carbenoxolone, a drug made from licorice, also sped ulcer healing in trials in the 1970s and 1980s. Evidence grade B · Traditional tier T3 Ongoing indigestion, reflux and bloating Good evidence — one randomised 50-person trial against placebo. In a trial of 50 people with ongoing indigestion, a licorice flavonoid extract (Gutgard) was tested against placebo for 30 days . The dose was 150 mg a day. Symptom scores fell more in the licorice group, including upper belly pain, nausea and bloating (Raveendra et al., 2012). Evidence grade B · Traditional tier T3 Eczema patches on the skin Early evidence — one small 60-person comparison study. In a study of 60 people, 2% licorice gel was rubbed on twice a day for two weeks. Redness, swelling and itch scores dropped, and results looked close to 1% hydrocortisone gel (Saeedi et al., 2003, Journal of Dermatological Treatment). This was one small study, so treat it as early work. Evidence grade C · Traditional tier T3 High testosterone in women, as seen in PCOS Early evidence — one small 32-person trial in healthy women, not in women with PCOS. In a trial of 32 healthy women, 3.5 g a day of a standard licorice extract was taken for two menstrual cycles. Blood testosterone went down (Armanini et al., 2004, Experimental and Clinical Endocrinology & Diabetes). No trial has tested this in women who have PCOS. Evidence grade C · Traditional tier T3 Helping to clear H. pylori, a stomach germ Long traditional use · not yet tested in trials — one small pilot study with no control group, plus lab dish work. In lab dishes, licorice flavonoids such as glabridin slowed H. pylori. That included strains that resist the drug clarithromycin. In a small pilot with no control group, a licorice flavonoid extract lowered H. pylori levels in infected people (Fukai et al., 2002, Life Sciences). Evidence grade D · Traditional tier T3 Sore, scratchy throat and cough Long traditional use · not yet tested in trials — lab studies and long traditional use only. Licorice turns slimy when wet, and this coating may soothe the throat lining. In lab tests, glycyrrhizin slowed some viruses that affect the airways. There are no strong human trials of licorice on its own for cough. Evidence grade insufficient · Traditional tier T3 Low energy blamed on 'adrenal fatigue' Long traditional use · not yet tested in trials — mechanism reasoning and tradition, with no clinical trials. In lab work, glycyrrhizin blocks an enzyme called 11-beta-HSD2. That lets cortisol, a stress hormone, last longer in tissue. No good trial has tested licorice in people with a real adrenal diagnosis. Evidence grade insufficient · Traditional tier T3 What Licorice Root has not been shown to do It has not been shown to clear H. pylori on its own, without standard drug therapy. It has not been shown to help people with diagnosed adrenal insufficiency; 'adrenal fatigue' is not a recognised medical diagnosis. It has not been shown in good human trials to stop or calm a cough when used alone. Its antiviral effect has only
