Viral Hepatitis and Licorice
Treatments made from licorice root are often used to treat hepatitis in Japan.1 In some cases, licorice extracts are used intravenously.27,28
Licorice may improve liver function and reduce mortality in people with hepatitis. The extract of licorice root is glycyrrhizin. This substance has anti-inflammatory and cytoprotective properties,1 so licorice probably helps treat hepatitis by reducing inflammation and cell damage in the liver.
Research evidence on the use of licorice products to treat hepatitis are mixed. So far, licorice shows more potential in animal studies than in human studies.1
In the United States, licorice can be found in oral form as an over-the-counter supplement. Oral forms of licorice come in various preparations--solid dry powder; powdered root; and fluid extract. Recommended dosage:1
- Solid dry powder: 250-500 mg, three times daily
- Powdered root: 1-2 gm, three times daily
- Fluid extract: 2-4 mL, three times daily
Note: 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 Side Effects and Warnings.) Individuals who wish to take a higher dose should do so only under the supervision of a physician.
- Naturopathic doctor
- Integrative MD
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. 1 Such effects are especially dangerous for people who take the drug digoxin or medications that deplete the body of potassium (such as thiazide and loop diuretics ), or who have high blood pressure, heart disease, diabetes, or kidney disease.
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. 2 For a person who weighs 130 pounds, this works out to 12 mg of glycyrrhizin daily. Based on a typical 4% glycyrrhizin content, this is the equivalent of 0.3 grams of licorice root.
Whole licorice may have other side effects as well. For example, it appears to reduce testosterone levels in men. 3 For this reason, men with impotence , infertility , or decreased libido may wish to avoid this herb. Licorice may also increase both the positive and negative effects of corticosteroids such as prednisone and hydrocortisone cream. 4 5 In addition, some evidence suggests that licorice might affect the liver's ability to metabolize other medications as well, but the extent of this effect has not been fully determined. 6 Whole licorice possesses significant estrogenic activity, 7 and some evidence indicates that licorice increases risk of premature birth. 8 For these reasons, it shouldn't be taken by pregnant or nursing women, or women who have had breast cancer.
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:
- Digoxin : Long-term use of licorice can be dangerous.
- Thiazide or loop diuretics : Use of licorice might lead to excessive potassium loss. 9
- Corticosteroid treatment : Licorice could increase both its negative and positive effects. Do not take licorice internally if using corticosteroids.
- Aspirin or other anti-inflammatory drugs : Regular use of DGL might help lower the risk of ulcers.
- Rakel, D. (2007). Integrative Medicine (2nd Ed.). Philadelphia, PA: Saunders Elsevier.
- 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]
- Arase Y, Ikeda K, Murashima N, et al. The long term efficacy of glycyrrhizin in chronic hepatitis C patients. Cancer. 1997;79:1494-1500
- Sigurjónsdóttir 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. 15(8):549-52.
- van Gelderen CE, Bijlsma JA, van Dokkum W, Savelkoul TJ. Glycyrrhizic acid: the assessment of a no effect level. Hum Exp Toxicol. 19(8):434-9.
- Armanini D, Palermo M. Reduction of serum testosterone in men by licorice. N Engl J Med. 1999;341:1158.
- Teelucksingh S, Mackie AD, Burt D, McIntyre MA, Brett L, Edwards CR. Potentiation of hydrocortisone activity in skin by glycyrrhetinic acid. Lancet. 335(8697):1060-3.
- Kumagai A, Nanaboshi M, Asanuma Y, et al. Effects of glycyrrhizin on thymolytic and immunosupressive action of cortisone. Endocrinol Jpn. 1967;14:39-42.
- Budzinski JW, Foster BC, Vandenhoek S, et al. An in vitro evaluation of human cytochrome P450 3A4 inhibition by selected commercial herbal extracts and tinctures. Phytomedicine. 2000;7:273-282.
- Zava DT, Dollbaum CM, Blen M. Estrogen and progestin bioactivity of foods, herbs, and spices. Proc Soc Exp Biol Med. 217(3):369-78.
- Strandberg TE, Järvenpää AL, Vanhanen H, McKeigue PM. Birth outcome in relation to licorice consumption during pregnancy. Am J Epidemiol. 153(11):1085-8.
- Shintani S, Murase H, Tsukagoshi H, et al. Glycyrrhizin (licorice)-induced hypokalemic myopathy. Report of two cases and review of the literature. Eur Neurol. 1992;32:44-51.