Licorice Root (Glycyrrhiza glabra)

Glycyrrhizin is one of the active constituents of licorice. It possesses antidepressant effects, and heals mucous membranes of the digestive tract. It may cause peripheral edema (fluid retention), which goes away when licorice is stopped. Because glycyrrhizin can cause high blood pressure and other problems, it should only be taken on the advice of a health care practitioner.

DGL stands for De-Glycyrrhizinated Licorice. Glycyrrhizin has been shown to increase blood pressure and cause water retention. Since the glycyrrhizin is removed, DGL does not cause these potentially harmful side effects.

Licorice can be taken in the following forms:

  • Dried root: 1 to 5g as an infusion or decoction three times per day
  • 250-500mg (standardized extract), 3 times a day
  • Licorice 1:5 tincture: 2 to 5ml three times per day
  • DGL extract: 0.4 to 1.6g three times per day for peptic ulcer
  • DGL extract 4:1: in chewable tablet form 300 to 400mg 20 minutes before meals for peptic ulcer

Capsules and liquid extracts made from powdered licorice root are the most commonly available single agent forms of licorice in the United States.


Licorice Root (Glycyrrhiza glabra) can help with the following


Heartburn / GERD

A sometimes effective way to resolve reflux and indigestion is the use of DGL licorice for a few days.


Gastric/Peptic Ulcers

Licorice root, particularly deglycyrrhized licorice, can be a useful adjunct to antibiotic treatment because it accelerates the healing of the stomach lining. Deglycyrrhized licorice root (DGL) and glutamine have been used to get people off of antacids, H2 blockers and proton pump inhibiters (PPI). A typical dose of DGL will be 500mg tid either with or without a meal.

In a study of DGL in gastric ulcers, 33 gastric ulcer patients were treated with either DGL (760mg TID) or a placebo for one month. There was a significantly greater reduction in ulcer size in the DGL group (78%), than in the placebo group (34%). Complete healing occurred in 44% of those receiving DGL, but in only 6% of the placebo group. [Gut 1969:10; pp.299-303]

Emergency Care  

Upcoming Surgical Procedure

High doses of licorice may elevate blood pressure or promote an electrolyte imbalance from potassium loss.


Low Adrenal Function / Adrenal Insufficiency

If cortisol levels are low, one of the ways to sustain more normal levels is to slow or inhibit its breakdown. This can be accomplished naturally.

The only known readily available inhibitors of the enzyme that deactivates cortisol (11 beta-HSD) are glycyrrhizic acid (found in licorice root extract), progesterone, and flavonoids (in grapefruit). The concept of extending cortisol bioactivity via 11 beta-HSD inhibition is well established, but the manner in which progesterone alters 11 beta-HSD is not currently clear. You could eat 10 to 15 grapefruits or take licorice root extract to sustain cortisol levels. However, licorice root used regularly in large doses can produce high blood pressure, water retention, potassium wasting, and breast enlargement in men. A Naturopathic Doctor should be able to guide you in using licorice root alone or in combination with other adrenal agents.


Elevated Testosterone Level, Male

17 healthy males between 22 and 24 years of age consumed 7g/day of licorice tablets containing 7.6% glycyrrhizic acid over a 7-day period. On days 4 and 8, serum testosterone levels were decreased by 25%, with an increase in 17-hydroxyprogesterone and luteinizing hormone, and a slight but not significant reduction in free testosterone. [Exp Clin Endocrinol Diabetes. 2003;111: pp.341-343]


Low Testosterone Level

17 healthy males between 22 and 24 years of age consumed 7g/day of licorice tablets containing 7.6% glycyrrhizic acid over a 7-day period. On days 4 and 8, serum testosterone levels were decreased by 25%, with an increase in 17-hydroxyprogesterone and luteinizing hormone, and a slight but not significant reduction in free testosterone. [Exp Clin Endocrinol Diabetes. 2003;111: pp.341-343]

The Immune System  

Canker Sores (Aphthous Ulcers)

For acute treatment, DGL (de-glycerrizinated licorice root) topically may prove to be of benefit. A mixture of DGL and warm water applied to the inside of the mouth may shorten the healing time for mouth ulcers. This DGL mixture is made by combining 200mg of powdered DGL and 1 cup or less (250ml) of warm water. Swish in the mouth for 2 to 3 minutes twice per day for one week. The use of ordinary licorice root powder may provide benefit also. [J Assoc Physicians India 1989; 37: p.647]

Jeff Haley of Orahealth USA has invented a licorice product called Cankermelts-GX. It is entirely natural and held in place with an oral patch. It is now available for sale from and some chain drug stores, where it has received high rankings from reviewers.


Herpes I

The topical application of licorice extracts containing glycyrrhiza may hasten recovery of oral herpes lesions.


STD Herpes II

Licorice root contains antiviral substances, like glycyrrhiza. Some doctors recommend creams or gels containing licorice be applied 3 to 4 times per day. Sprinkling the contents of a capsule of licorice root extract containing glycyrrhiza upon open herpes lesions may shorten the healing time.


Anorexia / Starvation Tendency

Possesses antidepressant effects, and heals mucous membranes of the digestive tract.



Organ Health  


250 to 500mg three times per day. Do not take licorice if you have high blood pressure. One of the active constituents in licorice, glycyrrhizin, is commonly used in Japan as an injected therapy for hepatitis B and C.[1] [2] Glycyrrhizin also blocks hepatitis A virus from replicating in test tubes.[3] It is not known whether oral licorice extracts that are high in glycyrrhizin are effective against hepatitis.

[1] Suzuki H, Ohta Y, Takino T, et al. Effects of glycyrrhizin on biochemical tests in patients with chronic hepatitis. Double blind trial. Asian Med J 1983;26: pp.423-38
[2] Yasuda K, Hino K, Fujioka S, et al. Effects of high dose therapy with Stronger Neo-Minophagen C (SNMC) on hepatic histography in non-A, non-B chronic active hepatitis. In Viral Hepatitis C, D, E, ed. T Shikata, RH Purcell, T Uchida. Amsterdam: Excerpta Medica, 1991, pp.205-9
[3] Crance JM, L’eveque F, Biziagos E, et al. Studies on mechanism of action on glycyrrhizin against hepatitis A virus replication in vitro. Antiviral Res 1994;23: pp.63-76



Glycyrrhizin, found in licorice root, shows steroid-Iike activity and has a long history of use as an anti-inflammatory and anti-allergic agent, actions which have now been documented. Glycyrrhiza is an expectorant, which can be useful for relieving asthma.


Bronchitis, Acute

Licorice root, among other herbs, is a commonly-used expectorant to ease mucus removal in bronchitis.


Polycystic Ovary Syndrome (PCOS)

In a 1982 trial, eight anovulatory infertile women with elevated testosterone were investigated for lowering serum testosterone levels and inducing regular ovulation by a formula containing equal parts of peony root (Paeonia lactiflora) and licorice root (Glycyrrhiza glabra). Serum testosterone levels were significantly lowered in seven patients by doses of 5-10 grams of the combination daily for 2-8 weeks. Six of seven patients ovulated regularly and two of six patients conceived (Yaginuma et al.) In a similar trial in 1988, a significant reduction of circulating testosterone occurred in 18 of 20 female subjects with PCOS (Takahashi et al.). Five of the 18 became pregnant. In the above trials, it was not established which plant or plant constituents altered the testosterone levels. In 1991, researchers performed in vitro tests of the effects of several plant constituents from peony and licorice on rat ovary cells, and suggested that glycyrrhetic acid, a metabolite of glycyrrhizin in humans, inhibits the conversion of androstenedione to testosterone. Armanini et al. suggested that glycyrrhizin, or its metabolites, act on the enzymes that convert 17-hydroxy-progesterone to androstenedione, effectively lowering testosterone.

For example, equal parts of Mediherb extracts can be mixed together and given at a dose of 1/2 to 1 teaspoon of the mixture, 2-3 times per day. Treatment can continue for six months with a break of at least one week every 4-6 weeks.



Possible Pregnancy-Related Issues

A high consumption of licorice (glycyrrhizin 500mg per week) was associated with an increased risk of preterm delivery in a study Finnish women. [Am J Epidemiol 2002;156(9): pp.803-5]


May do some good
Likely to help
May have adverse consequences
Reasonably likely to cause problems


Mucous Membranes

The membranes, such as the mouse, nose, anus, and vagina, that line the cavities and canals of the body which communicate with the air.


Abnormal accumulation of fluids within tissues resulting in swelling.


Liquid prepared by boiling plant material in water for a period of time.


(mg): 1/1,000 of a gram by weight.


An alcohol or water-alcohol solution, usually referring to a preparation from herbal materials.

Peptic Ulcer

A general term for gastric ulcers (stomach) and duodenal ulcers (duodenum), open sores in the stomach or duodenum caused by digestive juices and stomach acid. Most ulcers are no larger than a pencil eraser, but they can cause tremendous discomfort and pain. They occur most frequently in the 60 to 70 age group, and slightly more often in men than in women. Doctors now know that there are two major causes of ulcers: most often patients are infected with the bacteria Helicobacter pylori (H. pylori); others are regular users of non-steroidal anti-inflammatory drugs (NSAIDS), which include common products like aspirin and ibuprofen.


Lesion on the skin or mucous membrane.

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