Glycyrrhizin: An old weapon against a novel coronavirus

Phytother Res. 2021 Feb;35(2):629-636. doi: 10.1002/ptr.6852. Epub 2020 Sep 9.


Currently, over 100 countries are fighting against a common enemy, the severe acute respiratory syndrome coronavirus (SARS-CoV)-2, which causes COVID-19. This has created a demand for a substance whose effectiveness has already been demonstrated in a similar scenario. Glycyrrhizin (GZ) is a promising agent against SARS-CoV-2 as its antiviral activity against SARS-CoV has already been confirmed. It is worthwhile to extrapolate from its proven therapeutic effects as there is a high similarity in the structure and genome of SARS-CoV and SARS-CoV-2. There are many possible mechanisms through which GZ acts against viruses: increasing nitrous oxide production in macrophages, affecting transcription factors and cellular signalling pathways, directly altering the viral lipid-bilayer membrane, and binding to the ACE2 receptor. In this review, we discuss the possible use of GZ in the COVID-19 setting, where topical administration appears to be promising, with the nasal and oral cavity notably being the potent location in terms of viral load. The most recently published papers on the distribution of ACE2 in the human body and documented binding of GZ to this receptor, as well as its antiviral activity, suggest that GZ can be used as a therapeutic for COVID-19 and as a preventive agent against SARS-CoV-2.

Keywords: ACE2; COVID-19; SARS-CoV-2; coronavirus; glycyrrhizin; prevention.

Publication types

  • Review

MeSH terms

  • Administration, Intranasal
  • Administration, Topical
  • Angiotensin-Converting Enzyme Inhibitors / administration & dosage
  • Angiotensin-Converting Enzyme Inhibitors / therapeutic use*
  • Antiviral Agents / administration & dosage
  • Antiviral Agents / pharmacokinetics
  • Antiviral Agents / therapeutic use
  • COVID-19 / epidemiology
  • COVID-19 Drug Treatment*
  • Chemoprevention / methods*
  • Glycyrrhizic Acid / administration & dosage
  • Glycyrrhizic Acid / pharmacokinetics
  • Glycyrrhizic Acid / therapeutic use*
  • Humans
  • Peptidyl-Dipeptidase A / drug effects
  • Peptidyl-Dipeptidase A / metabolism
  • SARS-CoV-2 / drug effects*
  • SARS-CoV-2 / physiology
  • Signal Transduction / drug effects
  • Therapies, Investigational / methods


  • Angiotensin-Converting Enzyme Inhibitors
  • Antiviral Agents
  • Glycyrrhizic Acid
  • Peptidyl-Dipeptidase A