Licorice (Glycyrrhiza glabra ) is a flavorful herb that has been used in food and medicinal remedies for thousands of years. Also known as "sweet root," licorice root contains a compound that is roughly 50 times sweeter than sugar. Licorice root has been used in both Eastern and Western medicine to treat a variety of illnesses ranging from the common cold to liver disease. This herb has long been valued as a demulcent (soothing, coating agent) and expectorant (rids phlegm and mucous from the respiratory tract) and continues to be used by health care professionals today to relieve respiratory ailments (such as allergies, bronchitis, colds, sore throats, and tuberculosis), stomach problems (including heartburn from reflux), inflammatory disorders, skin diseases, stress relief, and liver problems.

Licorice grows wild in some parts of Europe and Asia. A perennial that grows 3 - 7 feet high, licorice has an extensive branching root system. The roots are straight pieces of wrinkled, fibrous wood, which are long and cylindrical (round) and grow horizontally underground. Licorice roots are brown on the outside and yellow on the inside. Licorice supplements are made from the roots and underground stems of the plant.

Licorice root is often used to prevent and treat stomach ulcers. In fact, health care practitioners in Europe and Japan often prescribe a synthetic form of licorice for stomach ulcers. Although this drug is not available in the United States, many health care providers use deglycyrrhizinated licorice in gastric ulcers (DGL) with positive results. Deglycyrrhizinated licorice is a licorice supplement in which the component glycyrrhizin is removed. Glycyrrhizin has been reported to cause increases in blood pressure.

Animal studies and early trials in humans support the value of licorice for stomach ulcers. One animal study recently found that aspirin coated with licorice reduced the number of ulcers in rats by 50%. (High doses of aspirin often cause ulcers in rats). Earlier studies in humans have found that preparations containing glycyrrhizin (an active compound in licorice) may be as effective as leading anti-ulcer medications in relieving pain associated with stomach ulcers and preventing the ulcers from recurring. In one study, licorice root fluid extract was used to treat 100 patients with stomach ulcers (of which 86 had not improved from conventional medication) for 6 weeks. Ninety percent of patients improved; ulcers totally disappeared in 22 of these patients.

Emerging studies are beginning to suggest that licorice may also play a role in the treatment of heart disease. In one recent study, people with high cholesterol experienced a significant reduction in total cholesterol, LDL ("bad") cholesterol, and triglyceride levels after taking licorice root extracts for 1 month. The extract also reduced systolic blood pressure by 10%, although licorice may increase blood pressure in some individuals. These measures returned to their previous, elevated levels when the participants stopped taking the licorice supplements. Earlier studies in mice produced similar results. Licorice root extract reduced the risk of atherosclerosis ("hardening of the arteries") in these animals.

Preliminary studies also suggest that licorice may play a role in the treatment of human immunodeficiency virus (HIV). One early study of only 3 people with HIV suggested that intravenous glycyrrhizin may prevent replication of HIV, but larger studies have yet to duplicate these findings. A laboratory study found that glycyrrhizin (a component found in licorice) inhibited the growth of Japanese encephalitis virus in test tubes, but further studies in humans are needed to confirm these preliminary findings. Experimental studies also suggest that active compounds in licorice may have estrogen-like effects. It is not clear at this time whether such effects are helpful or harmful to people with breast cancer.

A recent human study found that a preparation of licorice may reduce body fat. Fifteen normal-weight subjects consumed licorice for 2 months (3.5 g a day). Body fat mass was measured before and after treatment. Licorice was able to reduce body fat mass and to suppress the hormone aldosterone. Another study found that a topical preparation of glycyrrhetinic acid (a component of licorice) was able to reduce the thickness of fat on the thigh in human subjects.

Human studies have also found that licorice supplements may act as a "phytoestrogen" in the body, meaning licorice may have effects like that of estrogen. It was found that licorice decreased symptoms of PMS and menopause, including mild depression. Recent laboratory studies found that licorice may also improve memory and cognition.

Despite these promising findings, there is ongoing debate in the scientific community regarding the value and side effects of licorice products. People who regularly consume large amounts of licorice (more than 20 g/day) may inadvertently raise blood levels of the hormone aldosterone, which can cause serious side effects, including headache, high blood pressure, and heart problems. Further studies are needed.

Glycyrrhizin, one of the main components found in licorice, is believed to contribute to the herb's healing properties. Laboratory studies have reported that glycyrrhizin reduces inflammation, promotes secretion of mucous (usually through coughing), soothes irritation, protects the stomach and gastrointestinal tract, and stimulates the activity of the adrenal glands (regulates cortisol, the stress hormone). The roots also contain coumarins, flavonoids, volatile oils, and plant sterols.

Licorice products are made from peeled and unpeeled dried root. There are powdered and finely cut root preparations made for teas, tablets, and capsules, as well as liquid extracts. Some licorice root extracts do not contain the compound that stimulates the adrenal glands (glycyrrhizin). These extracts are known as deglycyrrhizinated licorice (DGL), and do not seem to harm the adrenal glands or have the undesired side effects of other forms of licorice. DGL may be better for stomach or duodenal ulcers. Scientific studies show that DGL reduces inflammation and is as effective as some prescription drugs for gastric ulcers. In fact, DGL may offer protection against ulcer formation when taken with aspirin. In addition, it may enhance the effectiveness of antiulcer medications such as cimetidine (Tagemet) or ranitidine (Zantac).

Pediatric

For sore throat treatment in older children, a piece of licorice root may be chewed or licorice tea may be used. The appropriate dose of tea for a child should be determined by adjusting the recommended adult dose to account for the child's weight. Most herbal dosages for adults are calculated on the basis of a 150 lb (70 kg) adult. Therefore, if the child weighs 50 lb (20 - 25 kg), the appropriate dose of licorice for this child would be 1/3 of the adult dosage.

Adult

Licorice can be taken in the following forms:

• Dried root: 1 - 5 g as an infusion or decoction (boiled), three times daily
• Licorice 1:5 tincture: 2 - 5 mL, three times daily
• Standardized extract: 250 - 500 mg, three times daily, standardized to contain 20 % glycyrrhizinic acid
• DGL extract: 0.4 - 1.6 g, three times daily, for peptic ulcer
• DGL extract 4:1: chew 300 - 400 mg, three times daily 20 minutes before meals, for peptic ulcer

The use of herbs is a time-honored approach to strengthening the body and treating disease. Herbs, however, contain components that can trigger side effects and that can interact with other herbs, supplements, or medications. For these reasons, herbs should be taken with care, preferably under the supervision of a health care provider in the field of botanical medicine.

Licorice consumption may cause serious side effects. Too much of the component glycyrrhizin causes a condition called pseudoaldosteronism, which can cause an individual to become overly sensitive to a hormone in the adrenal cortex. This condition can lead to headaches, fatigue, high blood pressure, and even heart attacks. It may also cause water retention, which can lead to leg swelling and other problems. An overdose of glycyrrhizin can lead to harmful conditions such as high blood pressure and even heart attack.

Although the most dangerous effects generally only occur with high doses of licorice or glycyrrhizin, side effects may occur even with average amounts of licorice. Some people experience muscle pain or numbness in the arms and legs. Too much licorice can also cause weight gain. These problems can probably be avoided if dosages are kept within the recommended guidelines. It is safest, though, to have use of licorice monitored by your health care provider.

People with high blood pressure, obesity, diabetes, or kidney, heart, or liver conditions should avoid licorice. This herb should also not be used by pregnant or breast-feeding women or by men with decreased libido or other sexual dysfunctions. Use of any licorice product is not recommended for longer than 4 - 6 weeks.

If you are currently being treated with any of the following medications, you should not use licorice without first talking to your health care provider:

• Ace-inhibitors and diuretics -- If you are taking angiotensin-converting enzyme (ACE) inhibitors or diuretics to regulate blood pressure, do not use licorice products. Licorice could interfere with the effectiveness of these medications or could worsen possible side effects.
• Aspirin -- Animal studies suggest that licorice may reduce stomach irritation as well as the risk of stomach ulcers associated with aspirin.
• Digoxin -- Because licorice may dangerously increase the risk of toxic effects from digoxin, this herb should not be taken with this medication.
• Corticosteroids -- Licorice may increase the effects of corticosteroid medications. You should consult with your doctor before using licorice with any corticosteroids.
• Insulin -- Licorice may enhance some of the adverse effects of insulin.
• Laxatives -- Licorice may cause substantial potassium loss in people taking stimulant laxatives.
• Oral contraceptives -- There have been reports of women developing high blood pressure and low potassium levels when they took licorice while on oral contraceptives. Therefore, you should avoid licorice if you are taking birth control medications.

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