The efficacy of licorice root extract in decreasing transaminase activities in non-alcoholic fatty liver disease: a randomized controlled clinical trial

Phytother Res. 2012 Sep;26(9):1381-4. doi: 10.1002/ptr.3728. Epub 2012 Feb 6.


This study was performed to investigate the effects of licorice on non-alcoholic fatty liver disease (NAFLD). In this double blind randomized clinical trial, 66 patients were divided into case and control groups. All patients had elevated liver enzymes and had increased liver echogenicity (lipid accumulation) on sonography. The case group was treated with one capsule containing 2 g aqueous licorice root extract per day for 2 months while the control group was treated in the same manner with a placebo. Weight, body mass index (BMI) and liver transaminase levels were measured for each patient before and after the study. In the case group, the mean alanine aminotransferase (ALT) level decreased from 64.09 to 51.27 IU/mL and the aspartate aminotransferase (AST) level decreased from 58.18 to 49.45 IU/mL, which were statistically significant (p < 0.001 and p < 0.001). But in the control group, a drop in the ALT and AST levels was not statistically significant. The BMI difference before and after the study was not statistically significant in both groups. Despite the significant drop in liver enzymes following administration of licorice root extract, it is recommended that further studies that include histological examination are necessary.

Publication types

  • Randomized Controlled Trial

MeSH terms

  • Adult
  • Alanine Transaminase / blood
  • Alanine Transaminase / metabolism*
  • Aspartate Aminotransferases / blood
  • Aspartate Aminotransferases / metabolism*
  • Body Mass Index
  • Double-Blind Method
  • Fatty Liver / blood
  • Fatty Liver / enzymology*
  • Female
  • Glycyrrhiza / chemistry*
  • Humans
  • Liver / drug effects*
  • Liver / enzymology
  • Male
  • Middle Aged
  • Non-alcoholic Fatty Liver Disease
  • Plant Extracts / pharmacology*
  • Plant Roots / chemistry
  • Young Adult


  • Plant Extracts
  • Aspartate Aminotransferases
  • Alanine Transaminase