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. 1 2 3 To prevent this, manufacturers have found a way to remove glycyrrhizin from licorice, producing the safer product deglycyrrhizinated licorice (DGL).
Side effects
Licorice contains glycyrrhizic acid, the compound which is responsible for many of the reported side effects including:
DGL (deglycyrrhizinated licorice) does not have glycyrrhizic acid, and is therefore considered safer for use.
Possible Interactions
Licorice may interact with other medicines. If you are currently taking any of the following medications listed below, you should not use licorice without first consulting your doctor:
Precautions
Herbs have components that can trigger side effects and that can interact with other herbs, supplements, or medications. Before using licorice, tell your doctor or pharmacist about all of the medications you're taking.
Use of licorice during pregnancy should be avoided. Licorice has estrogenic activity and thought to have abortifacient effects.
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.
If you are taking:
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 eczema . 22 1 Licorice has constituents that increase the activity of naturally occurring (or artificially supplied) corticosteroids, 12 2 and this might explain some of the benefits seen. In addition, licorice contains licochalcone A, a substance hypothesized to have anti-inflammatory effects. 26 3
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. 9,10 4 Unfortunately, these studies do not prove that DGL was effective; antacids themselves can help heal ulcers, and in any case the studies were not double-blind . (For information on why this matters, see Why Does This Database Rely on Double-blind Studies? )
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.
A very preliminary study suggests that DGL might help prevent ulcers caused by aspirin and related medications (such as ibuprofen). 8 5
DGL has shown some promise for the treatment of ulcers . 7 1 Weak evidence hints that it might also help prevent ulcers caused by anti-inflammatory drugs. 8 2 DGL is also sometimes recommended for relieving the discomfort of canker sores and other mouth sores, and one small study suggests that a glycyrrhiza root extract may be effective when applied in the form of a dissolving patch. 29 3 Creams containing whole licorice (often combined with chamomile extract) are advocated for a variety of skin diseases, including eczema , psoriasis , and herpes , but as yet there is only supporting evidence for the first of these uses. (See What is the Scientific Evidence for Licorice ?).
Whole licorice, not DGL, is used as an expectorant for respiratory problems such as coughs and asthma .
Licorice has been suggested as a treatment for chronic fatigue syndrome (CFS) , based on the observation that people with CFS appear to suffer from low levels of certain adrenal hormones. The glycyrrhizin portion of licorice may relieve symptoms by mimicking the effects of these hormones. However, this is a fairly dangerous approach to treatment that should be tried only under medical supervision. In addition, studies of drugs that even more closely imitate adrenal hormones have not found benefit.
Licorice extracts are used intravenously in Japan for treatment of viral hepatitis . 27,28 4 However, there is no definite evidence that this treatment is effective; even if this were established, it would not imply that oral licorice would have a similar effect; furthermore, the high dosages used for treatment of chronic hepatitis may cause an elevation of blood pressure and other serious medical problems. Warning: Do not inject preparations of licorice designed for oral use.
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. 1-4 2 3 To prevent this, manufacturers have found a way to remove glycyrrhizin from licorice, producing the safer product deglycyrrhizinated licorice (DGL).
References
DGL has shown some promise for the treatment of ulcers . 1 Weak evidence hints that it might also help prevent ulcers caused by anti-inflammatory drugs. 2 DGL is also sometimes recommended for relieving the discomfort of canker sores and other mouth sores, and one small study suggests that a glycyrrhiza root extract may be effective when applied in the form of a dissolving patch. 3 Creams containing whole licorice (often combined with chamomile extract) are advocated for a variety of skin diseases, including eczema , psoriasis , and herpes , but as yet there is only supporting evidence for the first of these uses. (See What is the Scientific Evidence for Licorice ?).
Whole licorice, not DGL, is used as an expectorant for respiratory problems such as coughs and asthma .
Licorice has been suggested as a treatment for chronic fatigue syndrome (CFS) , based on the observation that people with CFS appear to suffer from low levels of certain adrenal hormones. The glycyrrhizin portion of licorice may relieve symptoms by mimicking the effects of these hormones. However, this is a fairly dangerous approach to treatment that should be tried only under medical supervision. In addition, studies of drugs that even more closely imitate adrenal hormones have not found benefit.
Licorice extracts are used intravenously in Japan for treatment of viral hepatitis . 4 However, there is no definite evidence that this treatment is effective; even if this were established, it would not imply that oral licorice would have a similar effect; furthermore, the high dosages used for treatment of chronic hepatitis may cause an elevation of blood pressure and other serious medical problems. Warning: Do not inject preparations of licorice designed for oral use.
Licorice is a legume, native to southern Europe and parts of Asia. This herbaceous perennial grows up to 1 meter tall. The flavor of licorice comes mainly from its aromatic compound called anethol. One of its components known as glycyrrhizin, is 50 times sweeter than sugar. Licorice has been used in food and medicinal remedies for thousands of years. Licorice has been used in ancient Greece, China, and Egypt, mainly as a treatment for gastritis and conditions of the upper respiratory tract. In ancient Egypt, licorice was prepared as a drink for ritual use to honor spirits of the pharaohs. Its use became widespread in Europe and Asia for treating a variety of disorders.
Today, Licorice is still being used as a remedy for different health problems, however not all its indications are supported by clinical evidence. Aside from its medicinal value, licorice has been used as a flavoring agent. Licorice is added as a sweetening agent in herbal medicines, lozenges, and tobacco products in amounts that will not produce therapeutic effects.
Most unpleasant effects of licorice have been attributed to the its chemical component called glycyrrhiza or glycyrrhizic acid. A process has been established to remove glycyrrhiza from licorice to eliminate the adverse metabolic effects of licorice. Its end product is called DGL (deglycyrrhizinated licorice), which is used for peptic ulcers, canker sores, and GERD 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. 1 2 3 To prevent this, manufacturers have found a way to remove glycyrrhizin from licorice, producing the safer product deglycyrrhizinated licorice (DGL).
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 eczema . 1 Licorice has constituents that increase the activity of naturally occurring (or artificially supplied) corticosteroids, 2 and this might explain some of the benefits seen. In addition, licorice contains licochalcone A, a substance hypothesized to have anti-inflammatory effects. 3
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. 4 Unfortunately, these studies do not prove that DGL was effective; antacids themselves can help heal ulcers, and in any case the studies were not double-blind . (For information on why this matters, see Why Does This Database Rely on Double-blind Studies? )
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.
A very preliminary study suggests that DGL might help prevent ulcers caused by aspirin and related medications (such as ibuprofen). 5
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.
DGL has shown some promise for the treatment of ulcers . 1 Weak evidence hints that it might also help prevent ulcers caused by anti-inflammatory drugs. 2 DGL is also sometimes recommended for relieving the discomfort of canker sores and other mouth sores, and one small study suggests that a glycyrrhiza root extract may be effective when applied in the form of a dissolving patch. 3 Creams containing whole licorice (often combined with chamomile extract) are advocated for a variety of skin diseases, including eczema , psoriasis , and herpes , but as yet there is only supporting evidence for the first of these uses. (See What is the Scientific Evidence for Licorice ?).
Whole licorice, not DGL, is used as an expectorant for respiratory problems such as coughs and asthma .
Licorice has been suggested as a treatment for chronic fatigue syndrome (CFS) , based on the observation that people with CFS appear to suffer from low levels of certain adrenal hormones. The glycyrrhizin portion of licorice may relieve symptoms by mimicking the effects of these hormones. However, this is a fairly dangerous approach to treatment that should be tried only under medical supervision. In addition, studies of drugs that even more closely imitate adrenal hormones have not found benefit.
Licorice extracts are used intravenously in Japan for treatment of viral hepatitis . 4 However, there is no definite evidence that this treatment is effective; even if this were established, it would not imply that oral licorice would have a similar effect; furthermore, the high dosages used for treatment of chronic hepatitis may cause an elevation of blood pressure and other serious medical problems. Warning: Do not inject preparations of licorice designed for oral use.
