The Romans called it Radix dulcis, meaning “sweet root.” The Germans called it “sweet wood.” The armies of Alexander carried it to allay thirst, the Sioux in North America chewed it for toothache, and medieval English governments taxed it. Licorice has been used in many ways by many cultures.
A shrubby perennial of the pea family, licorice is cultivated for its sweetness and medicinal properties. The roots are harvested at the end of the fourth year, when the sweet taste is strongest. As many as 20 known species are native to South Asia, Europe, and North America. Glycyrrhiza uralensis and G. glabra are most frequently used medicinally.
Licorice root has a variety of medicinal uses, and has been traditionally classed as anti-inflammatory, adrenal tonic, antiallergy, antimicrobial, cough-reducer, expectorant, and mild laxative. It has been extensively investigated, and many of its traditional uses have been verified through clinical trials.
Licorice is widely used for upper respiratory problems: sore throats, bronchitis, coughs, and excess catarrh. It soothes and reduces coughing, while its antiviral action is excellent for mouth ulcers and cold sores. The sweet taste makes licorice a popular addition to cough syrups and lozenges.
The healing effects of licorice make this herb a remedy for gastritis, peptic ulcers, and abdominal cramping. Some studies suggest that licorice can increase gastric juices by as much as 25 percent without altering the natural pH of the stomach, making licorice important for proper digestion.
Chemicals in licorice are metabolized by the body into molecules having a similar structure to some adrenal hormones. One of these hormones, cortisol, may be the basis of the anti-inflammatory effect of licorice. The herb is often added to formulas for chronic inflammatory conditions such as arthritic and rheumatic complaints.
Like all strong herbs, licorice must be treated with respect, and seeking the advice of a qualified natural health practitioner is recommended. While considered safe in low doses, adverse effects are common if you take more than 20 g of the root per day. Susceptible individuals may experience side effects at much lower doses.
Possible adverse effects include increased blood pressure, water retention, headaches,
dizziness, and irregular heartbeat. The safety of licorice in pregnancy has not been established, and it should be avoided in any dose over 3 g a day.
Do not take licorice if you have an existing high blood pressure or heart condition, or if you are taking medications for high blood pressure or heart problems. Also avoid licorice if you are taking diuretics or using potassium supplements. Licorice has been reported to have negative effects on estrogen-sensitive conditions, on thyroid hormone production, and it should not be combined with prescription corticosteroids.
The commercial product, DGL (deglycyrrhizinated licorice), attempts to avoid adverse effects by reducing the glycyrrhizin content of the herb. (Glycyrrhizin, a component of licorice, is reportedly 50 times sweeter than table sugar.) DGL has proven effective for treating stomach ulcers and mouth sores, but needs to be mixed with saliva for best effect. For that reason, the preparation is normally available in a chewable tablet form. Chew a 300 mg tablet three times a day before meals and at bedtime. Follow the manufacturer’s recommendations, as dosages may vary.
Use the whole root to make a tea by steeping 1/2 tsp (2 g) dried root in 1 cup (250 mL) boiling water, or take 1/4 to 3/4 tsp (1 to 3 mL) tincture (1:5 ratio of dried herb to 45 percent alcohol extract). Take this tea three times a day, for a maximum of four to six weeks.
As one of our most versatile and effective herbs, licorice has proven its worth throughout history.
The Licorice List
Licorice has been shown to reduce allergy responses, which supports its use in the treatment of asthma, lupus, celiac disease, and topically in eczema or dermatitis preparations.
It has also been used in Bell’s palsy, chronic fatigue syndrome, vitiligo and melasma (skin pigmentation problems), polycystic ovarian syndrome, chronic urinary tract disease, infertility, psoriasis, and vasovagal syncope (where a sudden unexplained drop in blood pressure can cause fainting).
The root has been chewed for pain, and the leaves used to make drops for earache.