Licorice

    Researchedby:
    Daryl Nault

    Fact-checked

    by:

    Katie Jantz, Conni Covington
    Last Updated: August 27, 2024

    Licorice is the common name for plants of the Glycyrrhiza genus. Licorice has been used traditionally to treat and support the respiratory, gastrointestinal, cardiovascular, and genitourinary systems.

    What is licorice?

    Licorice is the common name for plants of the Glycyrrhiza genus. There are more than 30 species in the Glycyrrhiza genus, but the two most widespread are G. glabra and G. uralensis. Glycyrrhiza glabra has been identified primarily throughout Asia and Europe. Glycyrrhiza uralensis, on the other hand, is best known in Asia, but it is grown throughout Asia, Europe, and North America.[24][12]

    The word “glycyrrhiza” is derived from the Greek words “glycos” (sweet) and “rhiza” (root). Since the oil responsible for the characteristic licorice flavor also has some bioactive components, it is often considered to be a functional food.[25][12] As a flavoring agent, it is generally recognized as safe (GRAS) for consumption. However, US regulations restrict the maximum glycyrrhizin content in food products to less than 0.1% for baked goods, beverages, seasonings, and as a flavor enhancer, while confectionaries like gum (1.1%), soft candies (3.1%), and hard candies (16.0%) can contain more.

    Glycyrrhizin is the component of licorice frequently cited as being responsible for its effects. However, licorice also contains other bioactive compounds including flavonoids, coumarins, and polyphenols like glabridin, quercetin, liquiritigenin and licochalcone.[12][26][27][28][29]

    What are the known traditional, historical, and cultural uses of licorice?What is deglycyrrhizinated licorice, and does it have the same risks and benefits as regular licorice?

    What are licorice’s main benefits?

    Licorice may aid digestive health through reductions in ulcerations, pain, and inflammation along the digestive tract, which may explain why it is considered to improve symptoms of functional dyspepsia (indigestion) and ulcerative colitis.[30][31][32][33] Similarly, licorice has shown some evidence of relieving the symptoms of postoperative sore throat, rheumatoid arthritis, and atopic dermatitis by suppressing T-cell activity and reducing inflammation (See this FAQ for details.)[34][35][36][37][38][39][40][41]

    It is also possible that licorice might prevent tumor growth, protect cells from chemotherapy damage, benefit some cardiovascular measures, and aid in neurological conditions like dementia and epilepsy.[42][43][44][45][46][47][48][49][50][51][52] These findings are promising, but they generally still require further human-based clinical evidence before they can be considered conclusive.

    Does licorice affect hormones?Does licorice affect digestive health?Does licorice affect immune function?Does licorice affect neurological or cardiovascular health?

    What are licorice’s main drawbacks?

    Licorice intoxication or overdose is possible and has been associated with death and rhabdomyolysis (muscle breakdown due to low potassium) in case studies.[53][10][11] In one small study, 3 of 4 people who consumed 200 grams of licorice in under an hour reported feelings of nausea and fatigue which correlated with serum glycyrrhizin levels.[53]

    The glycyrrhizin component of licorice in particular may raise blood pressure in individuals with hypertension.[4][54][55] However, supplements with reduced (or undetectable) glycyrrhizin content may not be associated with the same adverse effects.[56]

    High doses of licorice (>500 mg of glycyrrhizin) are known to increase cortisol levels, decrease testosterone, and alter estrogen receptor activity.[57][58][3][5][6][7][8][59][60][61][62][63] Some of the hormonal effects of licorice (including increases in parathyroid hormone and decreases in DHEA) may be sex dependent.[64][65] Though licorice shows some promise for body fat reduction, these results are still conflicting, and it is possible that weight can increase through water retention.[66][4][67][68]

    How does licorice work?

    Glycyrrhizin (and its other forms, glycyrrhetinic and glycyrrhizic acid) is one of the more notable components of licorice, likely due to its high content and bioavailability.[69][70][71][72] One mechanism of glycyrrhizin seems to be its ability to inhibit enzymes, particularly along hormonal pathways. In clinical studies, these enzymatic inhibitions may produce effects such as increased cortisol and reduced testosterone.[57][58][3][9][73][74][60] Preclinical evidence suggests that the enzymatic inhibition by glycyrrhizin might also improve insulin sensitivity (via increased lipoprotein lipase activity), increase lipolysis (via hormone-sensitive lipase activation), and enhance the antiproliferative effects of corticosteroids.[75][76][77][78][79][80] Glycyrrhizin also might provide cardioprotection and relief of stomach cramps.[81][82][83][84][85][86]

    Flavonoid groupings, such as glabridin and liquiritigenin, and phenols such as licochalcone A are also found in licorice and may provide other health benefits. Dietary consumption of glabridin may protect LDL cholesterol from oxidation, slowing the progression of atherosclerosis.[51][52]

    In preclinical (animal) studies, glabridin and licochalcone A have shown anti-inflammatory effects through the inhibition of NF-kB activation.[87][88] Licochalcone A and liquiritigenin both may reduce cytokine release, relax intestinal muscles, and have antitumor properties.[43][45] Glabridin may also reduce fat storage and/or act as a selective estrogen receptor modulator,[89][90] and liquiritigenin may reduce the absorption of lipids from the intestines.[91] However, further research is needed to confirm these findings clinically in humans.

    What are other names for Licorice?

    Note that Licorice is also known as:

    • Liquorice
    • Yashtimadhu
    • Glycyrrhiza
    • Glycyrrizha uralensis
    • Glycyrrizha glabra

    Dosage information

    When used as a treatment, licorice can be found in a wide variety of formulations, including but not limited to tablets, powder, drops, chewables, capsules, tea, dried root infusions, decoctions, syrups, tinctures, and gum. It’s also found in a wide variety of candies, foods, beverages, and even cigarettes as a flavoring agent.[12] The glycyrrhizin content of licorice products varies by the species and origin of the raw licorice root; according to one study, it can range from from 0.3–8.3% (with an average around 3.3%), but other studies have cited it as high as 6–10%.[13][14] Deglycyrrhizinated licorice is also available, and it has been processed to reduce glycyrrhizin content below detectable levels.

    To treat ulcers and gastritis, daily dosing can range from 1–15 grams.[15] However, it should be noted that individual characteristics (sex, age, health status, etc.) and how the root has been prepared may affect its action or potency.[15][1][16]

    Traditional Chinese Medicine recommends 8–15 grams of licorice extract for general health and up to 100 grams for use in health conditions, but it is commonly found combined with other ingredients in this context.[1] The components of licorice appear to interact with other nutrients, typically in a synergistic manner. When combined with lycopene, it may work synergistically to prevent LDL oxidation.[17] If taken alongside oriental bezoar and Panax ginseng, it is thought to synergistically reduce stress-induced biomarker changes.[18][19] Combining licorice with cranberry may confer a synergistic anti-inflammatory and antibacterial effect.[20][21][22][23]

    Frequently asked questions

    What is licorice?

    Licorice is the common name for plants of the Glycyrrhiza genus. There are more than 30 species in the Glycyrrhiza genus, but the two most widespread are G. glabra and G. uralensis. Glycyrrhiza glabra has been identified primarily throughout Asia and Europe. Glycyrrhiza uralensis, on the other hand, is best known in Asia, but it is grown throughout Asia, Europe, and North America.[24][12]

    The word “glycyrrhiza” is derived from the Greek words “glycos” (sweet) and “rhiza” (root). Since the oil responsible for the characteristic licorice flavor also has some bioactive components, it is often considered to be a functional food.[25][12] As a flavoring agent, it is generally recognized as safe (GRAS) for consumption. However, US regulations restrict the maximum glycyrrhizin content in food products to less than 0.1% for baked goods, beverages, seasonings, and as a flavor enhancer, while confectionaries like gum (1.1%), soft candies (3.1%), and hard candies (16.0%) can contain more.

    Glycyrrhizin is the component of licorice frequently cited as being responsible for its effects. However, licorice also contains other bioactive compounds including flavonoids, coumarins, and polyphenols like glabridin, quercetin, liquiritigenin and licochalcone.[12][26][27][28][29]

    What are the known traditional, historical, and cultural uses of licorice?

    The earliest documented uses of licorice for medicinal purposes can be traced back to ancient cultures spanning the Middle East (Assyria, Egypt) to Southeast Asia (China, India).[92] Licorice is considered essential to Traditional Chinese Medicine (TCM), where it is used for conditions of the cardiorespiratory, endocrine, and digestive systems. The relative ubiquity of licorice means it has been used on most continents of the world as a traditional medicine for a wide range of uses all throughout the body with both topical and systemic applications.[25][92][12][93][94]

    Twenty-eight different First Nations peoples of the Americas (notably the Dakota, Cheyenne, Blackfoot and Sioux) are known to have used licorice in traditional healing for over 20 different conditions and ailments. The most commonly cited uses for licorice among First Nations peoples include use as a throat aid, cough medicine, and toothache remedy.[95]

    What is deglycyrrhizinated licorice, and does it have the same risks and benefits as regular licorice?

    Glycyrrhizin is an active compound found naturally in licorice that is linked to several adverse effects (see this FAQ for details). Deglycyrrhizination is a process through which glycyrrhizin is removed from a licorice supplement, resulting in decglycyrrhizinated licorice (DGL).[14] DGL should theoretically have a reduced risk of glycyrrhizin-related adverse effects. However, glycyrrhizin may be desired in some instances, because it is a bioactive component (see this FAQ for details), and its desirability may depend on the individual and their reason for using it.

    DGL is commonly found at supplement and health food stores and would likely be labeled as such; however, it is up to the manufacturer to test and label their products accurately.

    What are licorice’s main benefits?

    Licorice may aid digestive health through reductions in ulcerations, pain, and inflammation along the digestive tract, which may explain why it is considered to improve symptoms of functional dyspepsia (indigestion) and ulcerative colitis.[30][31][32][33] Similarly, licorice has shown some evidence of relieving the symptoms of postoperative sore throat, rheumatoid arthritis, and atopic dermatitis by suppressing T-cell activity and reducing inflammation (See this FAQ for details.)[34][35][36][37][38][39][40][41]

    It is also possible that licorice might prevent tumor growth, protect cells from chemotherapy damage, benefit some cardiovascular measures, and aid in neurological conditions like dementia and epilepsy.[42][43][44][45][46][47][48][49][50][51][52] These findings are promising, but they generally still require further human-based clinical evidence before they can be considered conclusive.

    Does licorice affect hormones?

    Licorice inhibits an enzyme responsible for the conversion of cortisol to cortisone, which has been shown to increase the cortisol-to-cortisone ratio when the dosage of glycyrrhetinic acid is more than 500 mg per day.[57][5][7][8][64] Elevations in cortisol can lead to high blood pressure and metabolic alkalosis, mimicking a condition known as hyperaldosteronism.[6][5]

    Increases in parathyroid hormone levels have also been observed in women who took licorice (3.5 grams per day over 2 months).[65] Licorice can inhibit enzymes leading to a decrease in DHEA, but this effect may be more pronounced in men.[64]

    Licorice also appears to inhibit testosterone production through enzymatic inhibition, thus lowering testosterone levels.[59][60] This appears to be a dose-dependent response. Licorice extract taken at 5–7 grams daily (containing 500 mg of glycyrrhizic acid) resulted in testosterone reductions in men, but the levels returned to normal when they stopped. Lower dosages do not appear to significantly affect testosterone levels.[59][74][9][3][64]

    Phytoestrogens are also found in licorice. Glabrene and liquiritigenin, for example, may activate some estrogen receptors, while glabridin seems to selectively modulate them.[59][96][89][97][61][62]

    Does licorice affect digestive health?

    Licorice is known for its ability to heal ulcerations along the digestive tract. For example, applying licorice to oral ulcers over the course of a week resulted in smaller ulcers than no treatment at all.[98] Further clinical evidence from review studies suggested that licorice may be an effective treatment for reducing the pain, size, and healing time of oral canker sores.[30][31]

    Licorice appears to be effective for reducing the symptoms of functional dyspepsia (indigestion) and ulcerative colitis.[32][33] Several compounds in licorice are thought to relax the intestinal muscles, which may provide relief from intestinal cramping.[84][85][86][26]

    Licorice components (liquiritigenin and isoliquiritigenin) reduced the size of fat cells in fatty liver in mice through a variety of mechanisms, which hints at therapeutic possibilities, but human studies will be needed before this can be confirmed.[99][100][101][102][103][104] When combined with standard treatments, licorice might improve the liver function of children with acute hepatitis, but the evidence for this approach is rated as low or very low certainty.[32]

    There is limited evidence for licorice to reduce body fat, though glycyrretinic acid (topical application of 2.5% cream for one month) shows the most promise for fat reduction without weight change.[66][68] Individuals without overweight/obesity who took 3.5 grams of licorice per day orally for two months reported body fat reductions which were not attributable to the loss of retained water.[67] However, another study where the participants used licorice for four weeks (100 grams of licorice; 150 mg of glycyrrhetic acid) actually saw an increase in body mass index that was attributed to water weight, so the results are still conflicting.[4]

    Does licorice affect immune function?

    Licorice interacts with the immune system and has been associated with reduced macrophage oxidation and increased T-cell activity.[35][36][37][38] These anti-inflammatory properties may explain why licorice has been effective in reducing postoperative sore throat, enhancing the efficacy of rheumatoid arthritis medications, and reducing the symptoms of atopic dermatitis.[39][39][105][40][41]

    In animal studies, licochalcone A and liquiritigenin prevented the formation of new blood vessels that fed tumors, which could potentially reduce tumor size and/or growth.[43][44][45] Licorice extract might also preserve cells that are usually damaged by chemotherapy drugs, and it appears to work synergistically with chemotherapy in cancer treatment.[46][47][48]

    Does licorice affect neurological or cardiovascular health?

    Licorice root is a common ingredient in Traditional Chinese Medicine (TCM) formulas that are used for a variety of neurological conditions like dementia and epilepsy, but the evidence is mixed. Though there is some evidence to suggest that formulations containing licorice might be beneficial to memory or in addition to seizure medications, more research is needed before definitive conclusions can be drawn.[49][50] For neurologic conditions such as ALS and hereditary ataxia, evidence is still unclear regarding the efficacy of licorice as a therapy.[106][107]

    Mixed evidence also exists regarding the role of licorice in cardiovascular health. Overall, licorice may worsen hypertension, because glycyrrhizin in particular is believed to increase blood pressure.[4][54][55] Glabridin, one component of licorice, may help prevent the oxidation of LDL cholesterol, which could mitigate the damage done in conditions like atherosclerosis.[51][52] When used in combination with spironolactone (an androgen-receptor and glucocorticoid-receptor antagonist), licorice may mitigate adverse effects such as reduced blood volume.[108] However, the evidence for licorice improving blood flow or vascular health in general remains unclear.

    What are licorice’s main drawbacks?

    Licorice intoxication or overdose is possible and has been associated with death and rhabdomyolysis (muscle breakdown due to low potassium) in case studies.[53][10][11] In one small study, 3 of 4 people who consumed 200 grams of licorice in under an hour reported feelings of nausea and fatigue which correlated with serum glycyrrhizin levels.[53]

    The glycyrrhizin component of licorice in particular may raise blood pressure in individuals with hypertension.[4][54][55] However, supplements with reduced (or undetectable) glycyrrhizin content may not be associated with the same adverse effects.[56]

    High doses of licorice (>500 mg of glycyrrhizin) are known to increase cortisol levels, decrease testosterone, and alter estrogen receptor activity.[57][58][3][5][6][7][8][59][60][61][62][63] Some of the hormonal effects of licorice (including increases in parathyroid hormone and decreases in DHEA) may be sex dependent.[64][65] Though licorice shows some promise for body fat reduction, these results are still conflicting, and it is possible that weight can increase through water retention.[66][4][67][68]

    How does licorice work?

    Glycyrrhizin (and its other forms, glycyrrhetinic and glycyrrhizic acid) is one of the more notable components of licorice, likely due to its high content and bioavailability.[69][70][71][72] One mechanism of glycyrrhizin seems to be its ability to inhibit enzymes, particularly along hormonal pathways. In clinical studies, these enzymatic inhibitions may produce effects such as increased cortisol and reduced testosterone.[57][58][3][9][73][74][60] Preclinical evidence suggests that the enzymatic inhibition by glycyrrhizin might also improve insulin sensitivity (via increased lipoprotein lipase activity), increase lipolysis (via hormone-sensitive lipase activation), and enhance the antiproliferative effects of corticosteroids.[75][76][77][78][79][80] Glycyrrhizin also might provide cardioprotection and relief of stomach cramps.[81][82][83][84][85][86]

    Flavonoid groupings, such as glabridin and liquiritigenin, and phenols such as licochalcone A are also found in licorice and may provide other health benefits. Dietary consumption of glabridin may protect LDL cholesterol from oxidation, slowing the progression of atherosclerosis.[51][52]

    In preclinical (animal) studies, glabridin and licochalcone A have shown anti-inflammatory effects through the inhibition of NF-kB activation.[87][88] Licochalcone A and liquiritigenin both may reduce cytokine release, relax intestinal muscles, and have antitumor properties.[43][45] Glabridin may also reduce fat storage and/or act as a selective estrogen receptor modulator,[89][90] and liquiritigenin may reduce the absorption of lipids from the intestines.[91] However, further research is needed to confirm these findings clinically in humans.

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