Licorice is a demulcent (a medication that has a soothing effect), and an expectorant (a medication that helps expel mucus from the respiratory tract). The parts of the licorice plant that are used medicinally are the roots and the underground stems. A compound called glycyrrhizin can be extracted from licorice root, and is the active ingredient in medicinal licorice preparations.
There is animal research and preliminary human trials on the use of licorice preparations to treat stomach ulcers, heart disease, HIV, excess body fat, and pre-menstrual syndrome. Glycyrrhizin was shown to be beneficial in treating Helicobacter pylori infections. Glycyrrhizin prevented H. pylori, which causes infection and stomach ulcers, from adhering to the walls of the stomach.
There is only preliminary animal research on using glycyrrhizin to treat ulcerative colitis. At this time, there is no evidence that licorice would be beneficial to treat ulcerative colitis in humans. Therefore, it is not recommended.
Interactions With Other Drugs
Licorice may interact with several medications, including:
- Angiotensin-Converting Enzyme (ACE) Inhibitors: May alter the effectiveness or worsen adverse effects.
- Oral contraceptives: May increase the risk of high blood pressure and low potassium.
- Corticosteroids: Effects may be increased.
- Digoxin: The risk of toxic effects is increased.
- Diuretics: May alter the effectiveness or worsen adverse effects.
- Insulin: May worsen adverse effects.
- Laxatives: May interact to cause severe potassium loss.
Licorice has long been used to treat many conditions, but it can still have adverse effects. Licorice, or any herbal preparation, is best used under the supervision of a qualified practitioner. Moderate amounts of licorice could lead to muscle pain or numbness in the arms and legs or weight gain. Consumption of high doses of glycyrrhizin could lead to headaches, fatigue, water retention (edema), high blood pressure, or possibly a heart attack.
Licorice contains compounds that prevent the body from converting cortisol to cortisone. This could cause an excess of cortisol in the body, which can lead to high blood pressure and low potassium levels (hypokalemia). Even moderate levels of licorice can cause these potentially serious side effects.
The use of licorice is not advised for women who are pregnant or breastfeeding. Licorice can cause fluid retention and has also been associated with preterm labor.
Licorice should be avoided by anyone who has:
- Heart disease
- High blood pressure
- Kidney disease
- Liver disease
- Men with decreased libido or sexual dysfunction
- Myasthenia gravis
Anyone who experiences symptoms of fluid retention (such as puffy ankles or facial swelling), shortness of breath, headache, fatigue, or a numbness or burning sensation in the limbs should stop taking licorice and seek medical attention.
There is no evidence that licorice root is beneficial in treating IBD in humans, and therefore isn't recommended. In addition, serious side effects can occur even with moderate amounts of licorice. Any alternative remedies you are using should always be discussed with your physician or healthcare professional.
A.D.A.M. "Licorice." University of Maryland Medical Center 2010. 23 Jan 2010.
National Center for Complementary and Alternative Medicine. "Licorice Root." NCCAM Jun 2008. 21 Jan 2010.
Wittschier N, Faller G, Hensel A. "Aqueous extracts and polysaccharides from liquorice roots (Glycyrrhiza glabra L.) inhibit adhesion of Helicobacter pylori to human gastric mucosa." J Ethnopharmacol 2009 Sep 7; 125:218-223. 21 Jan 2010.
Yuan H, Ji WS, Wu KX, Jiao JX, Sun LH, Feng YT. "Anti-inflammatory effect of Diammonium Glycyrrhizinate in a rat model of ulcerative colitis." World J Gastroenterol 2006 Jul 28; 12:4578-4581. 21 Jan 2010.