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.[1][2][3][4] 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.[5][6][7][8][9][10][11] 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.[12][13][14][15][16][17] Glycyrrhizin also might provide cardioprotection and relief of stomach cramps.[18][19][20][21][22][23]
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.[24][25]
In preclinical (animal) studies, glabridin and licochalcone A have shown anti-inflammatory effects through the inhibition of NF-kB activation.[26][27] Licochalcone A and liquiritigenin both may reduce cytokine release, relax intestinal muscles, and have antitumor properties.[28][29] Glabridin may also reduce fat storage and/or act as a selective estrogen receptor modulator,[30][31] and liquiritigenin may reduce the absorption of lipids from the intestines.[32] However, further research is needed to confirm these findings clinically in humans.