(Glycyrrhiza glabra)


Excerpted from:

Herbal Tonic Therapies

By Daniel B. Mowrey

“To the Chinese, there is no other herb that acts on such a grand scale except, perhaps, Ginseng. But the Chinese include Licorice Root in more combinations than they do Ginseng or any other herb. It is considered the key to health. I consider Licorice Root to be one of the two or three most important herbs in the world.

“Licorice Root is one of the most biologically active herbs in the world, wherein it has found extensive therapeutic use. It has also been the subject of an enormous amount of research. There is immense potential underlying the frequent ingestion of this plant.

Stomach Ailments

“Licorice Root exerts a soothing action on the mucosal surfaces of the GI tract, and is frequently used to help these tissues heal. Certain Licorice Root derivatives have been experimentally proven as among the best anti-ulcer medications available. Whole Licorice Root and its derivatives appear to have the ability to inhibit gastric acid secretion.

“Good herbal laxatives should also contain herbs that are tonic to the organs of digestion, and which soothe and heal an inflamed GI tract, and that help to ameliorate whatever harshness might arise from the laxatives themselves. Licorice Root is among the best such adjuncts.

Skin Problems

“The conditions that increase the occurrence of acne-like symptoms during certain stages of the menstrual cycle may be affected by the consumption of Licorice Root. The anti-inflammatory properties of the root have been considered responsible for its effectiveness in the treatment of numerous skin disorders, including dermatitis, eczema, psoriasis, impetigo, and lichen planus.

Musculoskeletal Health

“The amazing anti-inflammatory actions of Licorice Root extend to the entire surface area of the body, both outside and inside. Not only the skin, but the mucous membranes of the gastrointestinal tract yield to the soothing and healing action of Licorice Root. The plant reinforces the body’s ability to withstand attack from virtually any kind of pathogen, and should therefore be considered a tonic for the musculoskeletal system.

Liver Health

“In Chinese medicine, Licorice Root is often used as a remedy for jaundice and is considered a great liver detoxifier. Experimental work has validated the usefulness of Licorice Root in the treatment of hepatitis, cirrhosis, and related liver disorders.

Respiratory Health

“The herb has antitussive and expectorant actions. The demulcent and expectorant properties of Licorice Root are well accepted. For this reason, Licorice Root is often found in cough drops, lozenges and syrups.

Adrenal Glands

“Licorice Root appears to both mimic and potentiate the action of the adrenal-corticosteroids, though it also differs in action from these chemicals in several important ways.

“Licorice Root components have been found to exert a positive effect on the course of serious adrenal insufficiency, even in Addison’s Disease, which is characterized by near-total adrenal exhaustion. There is evidence that the effect depends on the presence of a small amount of glucocorticoid. In other words, if the disease has advanced to the stage of complete adrenal exhaustion, Licorice Root will be most beneficial if combined with a small amount of cortisone. Since the traditional treatment is the use of increasingly large amounts of cortisone, the ability to greatly reduce the dosage through the addition of Licorice Root represents a very attractive alternative.

Antimicrobial Action

“Licorice Root and its derivatives have recently shown extremely promising results as interferon inducers, especially in the treatment of hepatitis. And, the use of Licorice Root continues to be one of the most common treatments for chronic vaginal yeast infection.

Safety Data

“From time to time one reads about purported liver toxicity. These cases almost invariably involve potent extracts of the plant found in some licorice candies. The tonic property of the plant is absent, and so one action or another is allowed to come through without the balancing action of the other constituents. In passing it should be noted that any potential for toxicity in this herb can be completely counteracted by a simple potassium supplement to the diet.

“About 20% of the population is sensitive to the effects of ingesting high amounts of licorice extract. In these people, excess potassium is removed from the body, and sodium is retained. The symptoms, mainly hypertension and edema, mimic those that occur when too much of the hormone aldosterone is secreted by the adrenal glands. For this reason the licorice syndrome is called pseudoaldosteronism. Most victims of this condition either ingested large quantities of licorice extract-containing candy, were under treatment with carbenoxolone (an extremely concentrated extract), or had preexisting edematous tendencies which were exacerbated by the licorice candy. (Note that we are talking about European candies here; American licorice contains very little or no licorice extract).

“The toxicity of licorice has been greatly exaggerated by well-meaning quasi-herbalists and media types. Candy flavored with licorice extract has led to poisoning in individuals who habitually consumed half a pound to a pound or more daily, and in individuals who, for one reason or another, are extremely sensitive to the licorice extract (as found in ulcer cures and laxatives). But ingestion of the whole herb has not resulted in any significant toxicity. Pseudoaldosteronism can be easily prevented by the use of a high-potassium, low-sodium diet.

“As a general cautionary measure, persons with a history of hypertension, renal failure, or the current use of cardiac glycosides, may wish to avoid the use of Licorice Root altogether.”

Excerpted from:

Herbal Antivirals, Natural Remedies for Emerging & Resistant Viral Infections

By Stephen Buhner

“Licorice Root is an unusual medicinal. It is potently antiviral, moderately antibacterial, moderately immune potentiating, and a very potent synergist. It should rarely be used alone or in large doses for extended periods, especially if you are pregnant.

“One of the primary things to keep in mind when using Licorice Root is that the higher the glycyrrhizin content, the more antiviral the herb will be. If using the herb as an antiviral, you should not use deglycyrrhized Licorice Root. In the US, growers don’t test the glycyrrhizin content of their harvested roots. I think testing is warranted for two reasons: 1) It will be easier to create proper dosages of the herb in practice and 2) it makes it easier to determine the likelihood of side effects and how to dose the additives that, if taken with the herb, will reduce or eliminate the chance of those side effects.

Antiviral Dynamics

“Licorice Root has strong impacts on viruses. It is active against a wide range of viruses through multiple mechanisms. Licorice Root and its constituent glycyrrhizin act specifically by modulating membrane fluidity in both host and viral cells – the herb lowers membrane fluidity significantly. Enveloped viruses have a viral envelope surrounding them, covering their viral shell. The viral envelope is generally composed of glycoproteins that identify and bind to receptor cells on the surface of a host cell the virus wants to enter. Once the proper receptors are identified, the virus binds to them, fuses with the host cell, creates a pore in the cell, and enters it. The virus takes over the cell, reproduces, bursts it open, and spreads to other cells.

“Licorice Root and its constituents act by inhibiting the ability of enveloped viruses to fuse with host cells, create pores in the host cell membrane, and enter them. It does this by significantly reducing the membrane fluidity of both the host cell and the virus. As little as a 5% reduction in host cell membrane fluidity will reduce HIV infection by 56%.

“Excess cholesterol in the bloodstream serves to reduce host cell fluidity; the most interesting studies on the effects of Licorice Root and glycyrrhizin on viral infection occurred because glycyrrhizin is similar in shape to cholesterol. This stimulates speculation: Are cholesterol-lowering drugs affecting membrane fluidity across the board in those using them, thus increasing viral infections in that group?

“Glycyrrhizin is uptaken fairly quickly into the cell (due most likely to its cholesterol-like shape). It diffuses rapidly across the membrane and concentrates on the inner membrane surface (and possibly within the membrane itself), where it causes the membrane to become more rigid, significantly reducing the movement of compounds through it. Due to its nature glycyrrhizin is also uptaken by the viruses and incorporated into their viral envelope, which also becomes more rigid. Once this occurs, a virus’s ability to fuse with a host cell and create a pore in the membrane through which to enter the cell is inhibited.

“Licorice Root slows or ends a viral infection by an enveloped virus through its ability to reduce membrane fluidity. For other viruses, it is directly virucidal, and for others it stimulates the host immune system specifically to attack the invading virus. Chinese Skullcap and Licorice Root in combination should be considered the main antivirals to use for any infection.

Other Benefits

“Licorice Root is potently antioxidant, stimulates immune activity, is anticonvulsant, potently anti-inflammatory on skin eruptions, is liver protective, cerebroprotective, heals aspirin-induced ulcers, is antispasmodic to the lower intestine, is strongly antitussive, and protects mitochondria from damage.

Side Effects and Contraindications

“Generally, Licorice Root is nontoxic, even in high doses. However, long-term use, especially if you use the herb as a single (rather than in combination), and most especially if you use large doses, can cause a number of rather serious side effects. This herb should rarely be used in isolation or in large doses or for long time periods – that is, longer than 4 to 6 weeks. The side effects can be severe: edema, weak limbs (or loss of limb control entirely), spastic numbness, dizziness, headache, hypertension, hypokalemia (severe potassium depletion) – especially in the elderly. Additional problems are decreases in plasma renin and aldosterone levels, and at very large doses decreased body and thymus weight and blood cell counts. Essentially, this complex of symptoms is a condition called pseudoaldosteronism, which Licorice Root can and indeed does cause if you take too much of it for too long.

“However, you can add both glycine and L-cysteine to your Licorice Root protocol to limit the potential for pseudoaldosteronism if you are taking large doses of Licorice Root for extended periods. (Glycine, minimum 2000 mg daily; L-cysteine, minimum 500 mg daily). The addition of potassium (5000 mg daily) will also help prevent the hypokalemia. Again: Licorice Root should be taken in combination with other herbs – this reduces the tendency for side effects by itself. And, if you do need to take largish doses of Licorice Root, even with other herbs, for severe viral infections, please add these supplements to your regimen and carefully monitor for side effects.

Herb/Drug Interactions

“Licorice Root is highly synergistic. It is also additive. It should not be used along with estrogenic pharmaceuticals, hypertensive drugs, cardiac glycosides, diuretics such as thiazides, loop diuretics, spironolactone, amiloride, corticosteroids, hydrocortisone.”

Excerpted from:

Adaptogens in Medical Herbalism

By Donald Yance

“Licorice Root possesses a full spectrum of activities: antiviral, anti-inflammatory, antiallergic, demulcent, liver protective, and hormone balancing. Its triterpenes – mainly glycyrrhizin – possess a blocking ability against tumor-promoting agents.


“Licorice Root inhibits Epstein-Barr virus expression, which is associated with the development of certain cancers.


“Licorice Root can suppress the activities of 5-LOX and COX-2, key enzymes in the formation of proinflammatory eicosanoids from arachidonic acid.


“Licorice Root has an immune-regulating action useful for treating autoimmune diseases, allergies, and many forms of cancer.


“Licorice Root has been used for thousands of years for irritation to the mucous membranes of the urinary, respiratory, and digestive tracts; bronchitis; coughs; and stomach ulcers. Licorice Root has been found to be extremely effective for the prevention and treatment of peptic ulcers. It can be used effectively in the prevention and treatment of oral mucositis during and after radiation and chemotherapy in patients with cancer, especially of the head and neck region.

Liver Protective

“Licorice Root can be used in the treatment of hepatitis.

Hormone Balancing

“The flavonoids and isoflavonoids in Licorice Root possess hormone-regulating abilities.


“Licorice Root protects against carcinogen-induced DNA damage. Its polyphenols induce apoptosis in cancer cells. It has also been found to have potent antiangiogenic, antitumor activity. Licorice Root has been shown to suppress several different types of cancers, including pancreatic, prostate, breast, lung, skin, gastric, and endometrial, by affecting multiple pathways.

“Licorice Root increases overall vitality, and in combination with other herbs it moderates the characteristics of those plants, enhancing their actions as well as buffering the drying or astringent properties of many herbs. Licorice Root is used as a guide herb to enhance the activity of the other ingredients, reduce toxicity, and improve flavor. As such, there is no health risk associated with its moderate usage in this way. Because of its synergizing action, it is used in many formulas as a harmonizing agent.”

Therapeutic Dosing Range

“Crude herbs (teas and decoctions): 1 – 3 grams, most often in a formula mixed with several other herbs.

1:1 fluid extract: 2 – 4 ml, most often in a formula mixed with several herbs (1 tsp is 5 ml; 1 tsp is 6 – 7 dropperfuls; 2 – 4 ml = 2 1/2 to 5 1/2 dropperfuls).

Standardized extract (24% glycyrrhizic acid): 250 to 500 mg.

Deglycyrrhizinated licorice (DGL): two tablets (usually chewable, in 500 mg concentrations) two to four times daily between or after meals. DGL is a form of licorice that is glycyrrhizic acid-free. DGL will not induce fluid retention or cause a rise in blood pressure. It retains its demulcent properties and is very useful in relieving symptoms and promoting the healing of ulcers and mouth sores, as well as in relieving GI inflammation and heartburn. Though it can be used safely with no concern about inducing fluid retention or hypertension, it has no benefit for adrenal support [and no benefit as an antiviral].

Safety Profile

“Caution is advised for people who may have hypertension and are prone to fluid retention. Licorice Root, at high doses, because of its effect on aldosterone, can exacerbate or induce fluid retention, raising blood pressure.”

Excerpted from:

Adaptogens, Herbs for Strength, Stamina, and Stress Relief

By David Winston

“As an adaptogen, Licorice Root benefits the HPA axis function and the sympathoadrenal system (SAS). I frequently use it for people with adrenal insufficiency who have symptoms of fatigue, tiredness upon waking up in the morning, elevated cortisol and blood sugar levels, and frequent colds. Because it is an immunomodulator, Licorice Root can be used to stimulate immune system function in people with cancer and chronic fatigue immune deficiency syndrome and reduce excessive immune response in people with autoimmune disease (rheumatoid arthritis, lupus, scleroderma) and allergies (animal dander allergies and allergic asthma).

“Licorice Root also is of significant benefit for people with irritable bowel syndrome and inflammatory bowel disease. Most inflammatory bowel diseases are autoimmune in nature, so this herb’s ability to reduce excessive immune system response plus its anti-inflammatory effects make it a good choice for people with irritation, inflammation, or ulceration of the gastro-intestinal tract caused by these diseases. It is a prominent remedy for gastritis, gastric and duodenal ulcers, ileitis, and leaky gut syndrome (hyperpermeability).

“Other uses for this versatile herb include its use as a hepatoprotective agent to prevent drug- or viral-induced liver damage, and to balance the female reproductive system during menopause. Licorice Root also can be used topically to help heal herpes virus lesions (shingles, oral, or genital herpes).

Safety Issues

“There are many warnings in the medical and popular literature about the danger of Licorice Root. At the same time, it has been used safely and frequently in European, Middle Eastern, and Chinese medicine for millennia. Why the discrepancy? Licorice Root in excess can cause a condition known as hyperaldosteremia, in which a person retains sodium, loses potassium, and develops elevated blood pressure. This condition usually does not occur when this herb is used in small amounts in formulas, as is traditional. Cases of licorice-induced hyperaldosteremia usually involve eating excessive amounts of licorice solid extract (in real-licorice candies or chewing tobacco) or licorice tea (four or more cups a day). As with most things, moderation is important when using herbs, and traditional formulas and dosages often offer guidelines for safe use today.

“Avoid the use of Licorice Root for patients with hypertension. For anyone who is taking Licorice Root for an extended period of time, eating a diet that is high in potassium and low in sodium and checking blood pressure regularly are recommended.

Herb/Drug Interactions

“Licorice Root has been shown to increase the effectiveness of steroids such as prednisone and reduce their toxicity. It has been used for thousands of years in traditional Chinese medicine to harmonize herbal formulas and reduce toxicity of potentially dangerous herbs. Do not use Licorice Root with potassium-depleting diuretics, digoxin, or older types of antidepressants called monoamine oxidase inhibitors (MAOIs).”

Excerpted from:

The Green Pharmacy Herbal Handbook

By James Duke

Inflammation. “Licorice Root blocks prostaglandin production and inflammation. Although it supports the body’s release of cortisol, it also inhibits some of the more detrimental side effects of that natural hormone’s presence, such as increasing cholesterol synthesis in the liver and blocking the work of the adrenal glands and thymus. Topically, it’s a very good treatment for tendinitis, bursitis, gum inflammation, and such autoimmune inflammatory reactions as psoriasis.

Viral and bacterial infections. “Some 30 percent of Licorice Root’s dry weight consists of antibacterial substances, and its saponins improve the body’s ability to use other antibacterial compounds. Licorice Root also soothes irritated mucous membranes and contains nine different natural expectorants to break up phlegm and ease coughing. This alone makes it effective against colds and the flu. But there’s more: Good scientific evidence illustrates that Licorice Root fights viruses, including Epstein-Barr, herpes, hepatitis, and HIV. Glycyrrhizin prods the immune system into secreting more interferon, a basic antiviral chemical that prevents infectious foes from taking hold inside the body. It inhibits the villainous viral invasion in which the bug penetrates a cell and changes its genetic makeup to replicate and spread.

“In the liver, Licorice Root extract protects the organ from viral hepatitis. In the mouth, it heals canker sores. And it fights HIV.

Sex hormones. “Licorice Root offers something for both men and women. For men, it helps inhibit the conversion of testosterone into dihydrotestosterone, a form of the male hormone implicated in hair loss and prostate enlargement. For women, it appears either to raise or reduce estrogen levels, depending on the body’s need.

Sugar metabolism. “Licorice Root helps prevent the buildup (especially in the eye’s lens, the spine’s sciatic nerve, and the bloodstream) of a form of sugar called sorbitol, which figures in many of the complications of diabetes, including cataracts and vision deterioration, nerve damage, and kidney malfunction.

Medicinal properties for deglycyrrhizinated Licorice Root. “The large doses of Licorice Root sometimes necessary to generate a therapeutic effect can cause side effects, including high blood pressure, water retention, tissue swelling, weight gain, headache, lethargy, and skewed potassium and sodium levels. The side effects result from increasing levels of cortisol and other adrenal hormones. There is one instance in which the side effects are a welcome blessing: Addison’s Disease, in which the adrenal glands don’t secrete enough cortisol and aldosterone, leaving you weak and emaciated, among other consequences.

“Because of the adverse reactions, those who like to tinker with nature decided to strip Licorice Root of its glycyrrhizin and glycyrrhetinic acid and see what healing power remained from the rest of the phytochemicals. The effort has proved successful in treating ulcers and related stomach problems. Besides quelling spasms and reducing stomach acid, DGL (deglycyrrhizinated Licorice Root) protects and promotes the cells that line the intestinal tract, boosting blood flow to them and lengthening their lives. It also spares the stomach from aspirin’s erosive effect.

Precautions. “Licorice Root has gotten a bad rap from many medical authorities, mostly Americans. This herb possesses significant medicinal potential and should be regarded with the same cautious optimism as any other medicinal agent: good if used wisely, bad if used inappropriately. With moderate use in reasonable amounts, most people need not fear Licorice Root. Stick with the whole herb, not isolated extracts of this or that glycyrrhizin component. For an ulcer, use DGL; you’ll avoid side effects even if you take big dosages.

“Taking more than 50 grams of Licorice Root a day can elevate blood pressure, lower potassium levels, and cause water retention, among other problems. Given these potential problems, you probably shouldn’t take the herb if you have hypertension, kidney problems, liver problems, diabetes, or heart disease.”



Excerpted from:

American Herbal Products Association’s


Second Edition

Safety Class:

2b – Not to be used during pregnancy

2d – Other specific use restrictions as noted

Interaction Class:

B – Herbs for which clinically relevant interactions are biologically plausible


Not for use in persons with hypertension, liver disorders, edema, severe kidney insufficiency, low blood potassium, heart disease with edema, or congestive heart failure.

Drug and Supplement Interactions:

No interactions are expected at standard therapeutic doses. At higher doses or with long-term use, Licorice Root may potentiate potassium depletion of high-ceiling loop diuretics and thiazide diuretics, stimulant laxatives, and corticosteroids such as prednisolone; and may potentiate the action of cardiac glycosides such as digoxin.

One reference indicated a theoretical concern that Licorice Root may counteract the effects of oral contraceptives.

The above information applies to products that contain the compound glycyrrhizin and not to deglycyrrhizinated Licorice Root (DGL) products.

Adverse Events and Side Effects:

No case reports of adverse effects have been reported in persons using Licorice Root within the recommended dose (less than 50 grams daily) and treatment period (less than 6 weeks). Licorice Root is not for prolonged use or to be used in high doses except under the supervision of a qualified healthcare practitioner.

The mineralocorticoid effects of Licorice Root are well documented. Licorice Root may cause reversible potassium depletion and sodium retention when consumed in therapeutic dosages over a prolonged period. Most cases of adverse events associated with Licorice Root have been reported in persons consuming excessive amounts of licorice candies. These adverse events are attributed primarily to the action of the compound glycyrrhizin. Deglycyrrhizinated Licorice Root (DGL) is usually free of adverse effects.

No information on the safety of Licorice Root during lactation has been identified. Safety has not, however, been conclusively established.



Licorice Root cut

Licorice Root powder

Licorice Root liquid extract

Licorice Root glycerin extract


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