Licorice (Glycyrrhiza glabra)

Licorice comes from the root of the Glycerrhiza glabra plant that has a sweet, yellow wood. It has been used for centuries as a flavoring agent and to treat coughs and colds in Traditional Chinese Medicine. Although millions of pounds of licorice are imported into the United States every year, virtually none of it is used to produce the popular licorice candy. Most of the imported licorice is used in cough drops and to flavor tobacco. The flavoring used in licorice candy comes from anise oil, which resembles the flavor of licorice but without the medicinal properties.

Most of the licorice extracts used to treat various disorders contain no glycyrrhizin (de-glycyrrhizinated licorice). Glycyrrhizin is an extract of the plant’s root associated with side effects such as increased blood pressure and water retention. De-glycyrrhizinated licorice (DGL) is the safer form of herbal extract.

Claimed Health Benefits

Relieves pain associated with stomach ulcers
Helps relieve canker sores, heartburn
Topical licorice ointments can help with eczema, psoriasis, and herpes
Acts as a cough suppressant
Relieves pain of soar throats
Helps with chronic fatigue syndrome

Food Sources

None

Dose

Ulcers - chew one tablet containing 200-300 mg DGL before meals and at bedtime
Canker Sores – take 200 mg of DGL powder mixed with about ½ cup warm water, swish in mouth and then spit out - about three to four times a day.
Skin irritations – apply licorice cream to area two to three times a day.
Coughs – 1-2 g three times daily for no more than 1 week.
Chronic Fatigue Syndrome – speak with a physician as high doses are needed and side effects may result.

Evidence for Health Benefits

A human trial found that although patients had more immediate relief when taking an acid-blocking drug (Tagamet ®), DGL was just as effective at sustaining the healing of stomach ulcers (1).
Another human study found that using mouthwash that contained DGL helped heal canker sores quicker (2).
During the World War II era, a Dutch physician discovered that giving licorice extract to his patients suffering from ulcers significantly decreased their symptoms, but he also noted side effects such as swelling of the face and extremities (2).

Cautions

Licorice extract with glycyrrhizin can cause increased blood pressure, water retention, and loss of potassium if taken for more than two to three weeks.
Those with high blood pressure, heart disease, diabetes, or kidney disease should not take licorice extract.
Children and pregnant women should also avoid licorice extract.

References

1. Morgan AG, McAdam WAF, Pacsoo C, Darnborough A. Camparison between cimetidine and Caved-S in the treatment of gastric ulceration, and subsequent maintenance therapy. Gut 1982;23:545-51.

2. Das SK, Das V, Gulati AD, Singh VP. Deglycyrrhizinated licorice in aphthous ulcers. J Assoc Physicians India 1989;37:647.

3. Healthnotes, Inc. (2003) Helping People Lead Healthier Lives. http://www.healthwell.com/healthnotes/healthnotes.cfm?ContentID=2122006 Accessed July 28, 2003.

4. Quest Vitamins. (2000) Your Number One Source for Information on Health Conditions, Vitamins, Minerals, Supplements, Herbs, and More. http://www.questhealthlibrary.com/full_description.php?ElementID=337 Accessed July 28, 2003.

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