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.

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.

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.

• Peptic ulcer disease / gastric mucosal protection
• GERD and functional dyspepsia
• Upper respiratory tract irritation and cough
• Oral mucositis (chemotherapy-related mouth sores)
• Helicobacter pylori infection (adjunctive)
• Atopic dermatitis / eczema (topical)
• Polycystic ovary syndrome (PCOS) - hormonal modulation
• Adrenal fatigue / HPA axis support (traditional use)

• Recurrence of gastric ulcer (DGL maintenance therapy - supported by historical controlled trial data with carbenoxolone and DGL)
• Chemotherapy-induced oral mucositis (preventive mouthwash use - supported by RCT evidence)

• Licorice root tea (decoction) — Brewing dried licorice root directly provides glycyrrhizin and flavonoids in a bioavailable aqueous form; traditional decoctions deliver meaningful doses of active compounds but concentration varies significantly with preparation.
• Fennel (Foeniculum vulgare) — Does not contain glycyrrhizin but shares the characteristic anise-like flavor profile (from trans-anethole) and supports similar GI outcomes including spasmolysis, carminative action, and mucosal soothing—frequently combined with licorice root in herbal GI formulas.
• Anise seed (Pimpinella anisum) — Like fennel, anise seed contains trans-anethole and supports the same soothing GI and respiratory pathways as licorice root; it is a supportive dietary addition for individuals using licorice root therapeutically.
• Slippery elm (as food/herbal food product) — Slippery elm bark mucilage supports the same gastric mucosal coating mechanism as DGL licorice; often consumed as a gruel or lozenge alongside licorice root for GI conditions.
• Marshmallow root tea (Althaea officinalis) — Rich in mucilaginous polysaccharides that coat and protect inflamed mucosal tissue in the GI and respiratory tract via the same pathway as licorice root's demulcent action, making it a useful dietary/herbal companion.

• Hypertension (dose-dependent, glycyrrhizin-mediated, resolves with discontinuation)
• Hypokalemia (low blood potassium, can cause muscle weakness, cramps, fatigue, and in severe cases cardiac arrhythmia)
• Sodium and water retention / edema
• Pseudohyperaldosteronism syndrome (with high-dose or prolonged use of glycyrrhizin-containing products)
• Headache (particularly with higher doses)
• Nausea or gastrointestinal upset (uncommon, typically mild)
• Hormonal effects in women: potential alteration of estrogen/testosterone balance with prolonged use
• Preterm labor risk (avoid use during pregnancy - glycyrrhizin crosses the placental barrier and has been associated with adverse neonatal outcomes in epidemiological studies)
• Mild laxative effect (at high doses of root powder)

• Recommended daily: DGL (deglycyrrhizinated licorice): 760–1520 mg chewable tablets (typically 2 x 380 mg tablets) taken 20 minutes before meals, 2–3 times daily. Whole licorice standardized extract (for short-term use only): 200–600 mg of extract standardized to 20–25% glycyrrhizin, or up to 5–15 g of dried root equivalent; do not exceed 100 mg glycyrrhizin per day. Topical preparations: 1–2% glycyrrhetinic acid cream applied twice daily to affected areas.
• Best time of day: DGL chewable tablets are best taken 20 minutes before meals and at bedtime to maximize contact with gastric mucosa. Whole-root extracts or capsules can be taken with meals to reduce GI irritation. No strong evidence favoring a particular time for systemic indications.
• With or without food: DGL: Take without food (20 minutes before eating) for optimal mucosal coating effect. Whole licorice extract capsules: Take with food to improve tolerability and reduce GI discomfort.
• Time to effect: GI symptom relief with DGL: 1–4 weeks. Topical skin effects: 2–4 weeks. Hormonal/systemic effects with whole licorice: 4–8 weeks. Blood pressure elevation from glycyrrhizin can appear within days to weeks of high-dose use.
• How long to take it: DGL: Can be used for 8–12 weeks continuously for GI conditions; longer use at physician guidance is common given the low glycyrrhizin content. Whole licorice (glycyrrhizin-containing): Limit continuous use to 4–6 weeks maximum; cycle off for an equal period before resuming. Avoid whole licorice products indefinitely in individuals with hypertension, hypokalemia, kidney disease, or cardiovascular conditions. Reassess blood pressure and electrolytes if using whole licorice for longer than 2 weeks.