Efficacy and safety of licorice (Glycyrrhiza glabra) in moderately ill patients with COVID-19: a randomized controlled trial.

Licorice extract (glycyrrhizin), a potent antiviral, anti-inflammatory, and antioxidant remedy, is a potential therapeutic option for COVID-19. We evaluated the efficacy and safety of licorice in patients with moderate COVID-19. In this study, 60 patients with confirmed COVID-19 were randomly assigned in a 1:1 ratio to receive licorice (at a dose of 760 mg three times a day for seven days) or control groups. The primary outcomes were SPO2, body temperature, and respiratory rate (RR) after the end of the intervention. The findings indicated that SPO2, body temperature, and RR had no significant difference between the groups at the end of the intervention. However, CRP and ALT improved in the licorice group toward the baseline. The number of patients with worse prognoses, LOS, mortality, and the incidence of adverse events were not different between the groups at the end of the study. Licorice had no beneficial effect on the clinical symptoms of COVID-19. Moreover, this intervention demonstrated a safe profile of adverse events. The confirmation of the results of this preparatory trial requires more detailed multiple-center trials with a larger sample size.