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Licorice Root

Botanical name(s):

Glycyrrhiza glabra l. Family: Fabaceae

Other name(s):

licorice, sweet root

General description

Licorice is a herbaceous perennial commonly grown in southeastern Europe and western Asia. It has been used since ancient times as a flavoring agent and as an expectorant.

The medicinal parts of the licorice plant are the unpeeled dried roots and runners, and the rhizome (underground stem). Licorice contains the compound glycyrrhizin, which is 50 times sweeter than sugar. Excessive glycyrrhizin glycoside from eating too much licorice can result in fluid retention and hypertension.

Medically valid uses

The primary use of licorice is as a flavoring agent in products such as toothpaste, throat lozenges and tobacco. (Currently, most "licorice" candy is actually flavored with anise oil and not real licorice.)

A few clinical trials outside the United States have suggested that an injectable form of licorice extract may be beneficial for treating hepatitis C, but more research is needed.    

Unsubstantiated claims

Please note that this section reports on claims that have NOT yet been substantiated through scientific studies.

Licorice has been associated with a wide range of claims, including its possible use as an expectorant or anti-tussive (for cough and bronchitis), as an anti-allergenic or anti-inflammatory, as a hypolipidemic (for lowering cholesterol and triglyceride levels), as a preventative for plaque and tooth decay, as an anti-microbial or antiviral, as an anti-hepatotoxic (for protecting the liver), as an anti-cocaine hydrochloride and chloral hydrate, as an anti-snake venom, tetanus and globefish toxins, and as an immunosuppressive.

Licorice has also been used in the management of inflammation of the stomach (gastritis), viral liver disease, and skin conditions (when used topically).

Dosing format

Follow label recommendations.

Side effects, toxicity, and interactions

The side effects seen with high or prolonged dosages of licorice can be very serious. Licorice has an aldosterone-like effect, causing sodium retention and potassium loss.

Excessive use of licorice can lead to hypertension, which can be severe. Edema (swelling due to excess water retention), headache, lethargy (fatigue), and eventually heart failure or cardiac arrest can result from taking too much of this herb.

Poisoning from over-consumption of real licorice-containing candy or licorice-containing tobacco has been reported.

Do not take this herb in the presence of low serum potassium, chronic hepatitis, cholestatic liver disease, liver cirrhosis, abnormalities of heart rhythm, and other cardiovascular diseases, hypertension, severe renal insufficiency, hypokalemia, pheochromocytoma, aldosteronism, untreated hypothyroidism, or chronic alcohol use.

Women who are pregnant or breastfeeding should not use this herb.

Do not take licorice while fasting, as serious electrolyte imbalances may occur.

Thiazide diuretics may increase potassium loss when used in combination with licorice. The effects of digitalis can be indirectly increased since digitalis sensitivity is increased by low serum potassium levels.

Licorice may interfere with the effects of aldactone, a drug used to treat hypertension. Talk to your health care provider before you take licorice.

Additional information

Click here for a list of reputable websites with general information on nutrition.