• Oral Uses (DGL Form):
• Topical Uses (Whole Herb):
• Oral Uses (Whole Herb):
A member of the pea family, licorice root has been used since ancient times both as food and as medicine. In Chinese herbology, licorice is an ingredient in nearly all herbal formulas for the traditional purpose of "harmonizing" the separate herbs involved.
The herb licorice contains a substance called glycyrrhizin. When taken in high enough amounts, glycyrrhizin produces effects similar to those of the natural hormone aldosterone, causing fluid retention, increased blood pressure, and loss of potassium.
What Is Licorice Used for Today?
DGL has shown some promise for the treatment of ulcers
DGL is also sometimes recommended for relieving the discomfort of
Creams containing whole licorice (often combined with
Licorice has been suggested as a treatment for
Licorice extracts are used intravenously in Japan for treatment of
What Is the Scientific Evidence for Licorice?
Creams containing whole licorice (often combined with extract of chamomile) are in wide use as "natural hydrocortisone creams." However, there is only preliminary supporting evidence for this use. In one double-blind, placebo-controlled trial of 30 people, licorice gel at 2% was more effective than placebo or 1% gel for reducing symptoms of
Licorice has constituents that increase the activity of naturally occurring (or artificially supplied) corticosteroids,
Two controlled studies suggest that regular use of DGL in a combination product also containing antacids can heal ulcers as effectively as drugs in the Zantac family.
Furthermore, if it does work, DGL would have to be taken continuously to avoid ulcer recurrence. In some cases, drug treatment can prevent the recurrence of ulcers permanently by eradicating the bacteria Helicobacter pylori . There is no evidence as yet that DGL can do the same.
For supportive treatment of ulcer pain along with conventional medical care, the standard dose is two to four 380-mg tablets of DGL taken before meals and at bedtime. The same tablets can be allowed to slowly dissolve in the mouth for possible relief of mouth sore pain.
A typical dose of whole licorice is 5 to 15 g daily. However, we do not recommend the use of doses this high for more than a few weeks. For long-term consumption, about 0.3 g of licorice root daily should be safe for most adults. (See Safety Issues.) Individuals who wish to take a higher dose should do so only under the supervision of a physician.
For the treatment of eczema, psoriasis, or herpes, 2% licorice gel or cream is applied twice daily to the affected area.
Use of whole licorice has not been associated with significant adverse effects in the short term. However, two or more weeks of use may cause high blood pressure, fluid retention, and symptoms related to loss of potassium.
Such effects are especially dangerous for people who take the drug
Current evidence indicates that individuals who wish to take whole licorice on a long-term basis without any risk of these side effects should not consume more than 0.2 mg of glycyrrhizin per kilogram of body weight daily.
Whole licorice may have other side effects as well. For example, it appears to reduce testosterone levels in men.
Whole licorice possesses significant estrogenic activity,
Maximum safe doses for young children, nursing women, or those with severe liver or kidney disease have not been established.
It is believed, but not proven, that most or all of the major side effects of licorice are due to glycyrrhizin. For this reason, DGL has been described as entirely safe. However, comprehensive safety studies on DGL have not been reported.
Interactions You Should Know About
If you are taking:
6. Johnston B, McIsaac RL. The effect of some anti-ulcer agents on basal gastric mucosal blood flow and transmucosal flux of hydrogen and sodium ions in the conscious dog. Br J Pharmacol . 1981;73:308.
9. Morgan AG, Pacsoo C, McAdam WA. Maintenance therapy: a two year comparison between Caved-S and cimetidine treatment in the prevention of symptomatic gastric ulcer recurrence. Gut . 1985;26:599-602.
19. Sigurjonsdottir HA, Franzson L, Manhem K, Ragnarsson J, Sigurdsson G, Wallerstedt S. Liquorice-induced rise in blood pressure: a linear dose-response relationship. J Hum Hypertens . 2001;15:549-552.
24. Somjen D, Knoll E, Vaya J, et al. Estrogen-like activity of licorice root constituents: glabridin and glabrene, in vascular tissues in vitro and in vivo. J Steroid Biochem Mol Biol . 2004;91:147-155.
27. Orlent H, Hansen BE, Willems M, et al. Biochemical and histological effects of 26 weeks of glycyrrhizin treatment in chronic hepatitis C: A randomized phase II trial. J Hepatol . 2006 Jun 30. [Epub ahead of print]
29. Martin MD, Sherman J, van der Ven P, et al. A controlled trial of a dissolving oral patch concerning glycyrrhiza (licorice) herbal extract for the treatment of aphthous ulcers. Gen Dent. 2008;56:206-210;quiz 211-212,224.
Last reviewed April 2009 by EBSCO CAM Review Board
Please be aware that this information is provided to supplement the care provided by your physician. It is neither intended nor implied to be a substitute for professional medical advice. CALL YOUR HEALTHCARE PROVIDER IMMEDIATELY IF YOU THINK YOU MAY HAVE A MEDICAL EMERGENCY. Always seek the advice of your physician or other qualified health provider prior to starting any new treatment or with any questions you may have regarding a medical condition.
Copyright © 2007 EBSCO Publishing All rights reserved.