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.

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 been seen in lab dishes, not shown in people with respiratory infections.
• It has not been shown to improve PCOS itself; the testosterone trial was done in healthy women.

How to read this:

Grades reflect the human evidence behind each single use, not the plant as a whole. A means many matching human trials. B means at least one good human trial. C means small or early human studies. D means the human evidence is weak or mixed. Insufficient means lab work, animal work or tradition only. This page lists options and what studies found. It is not medical advice, and it is not a promise of results. Talk to your own clinician before you start.

What can Licorice Root help prevent?

• 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)

Which foods are rich in Licorice Root?

1. 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.
2. 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.
3. 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.
4. 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.
5. 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.

Practical Tips:

Licorice root itself is not found in significant concentrations in common dietary foods (licorice candy typically contains anise oil rather than true licorice root extract, and when it does contain glycyrrhizin, amounts are inconsistent and often insufficient for therapeutic effect). The foods listed above are functional allies that support the same GI mucosal, anti-inflammatory, and respiratory soothing pathways. Individuals using licorice root therapeutically should also emphasize a diet rich in fiber, fermented foods, and anti-inflammatory polyphenols to support gut mucosal health broadly. Foods high in potassium (bananas, potatoes, leafy greens, avocados) are especially important when using whole licorice formulations containing glycyrrhizin, to help offset the potassium-depleting mineralocorticoid effect.

What are the side effects of Licorice Root?

• 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)

Good to know:

Whole licorice root products containing glycyrrhizin are safe for most adults at moderate doses for short durations (up to 4–6 weeks), but high doses or prolonged use causes well-documented pseudohyperaldosteronism—a syndrome of hypertension, hypokalemia, sodium retention, and edema that is fully reversible upon discontinuation. DGL preparations, which have had glycyrrhizin largely removed, carry a substantially lower risk of systemic mineralocorticoid side effects and are generally considered safe for longer-term use. Individuals with pre-existing hypertension, kidney disease, heart failure, hypokalemia, or who are pregnant should avoid whole licorice root products.

How much Licorice Root should you take?

• 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.