Efficacy of licorice extract in the treatment of melasma: A randomized, double-blind, placebo-controlled clinical trial

Melasma is a common acquired disorder characterized by symmetric, hyperpigmented patches with an irregular outline, occurring most commonly on the face. The goal of this study was to evaluate the efficacy of a cream containing 4% licorice extract with a novel formulation based on solid lipid nanoparticles technology in the treatment of melasma. To the best of our knowledge, it is the first study designed to investigate the efficacy of this novel formulation in the treatment of melasma all over the world.
In this randomized, double-blind, placebo-controlled clinical trial, 44 women with clinical diagnosis of melasma referred to the Afzalipour hospital dermatology clinic were randomly allocated into two treatment groups of equal size. All the patients were interviewed and examined every four weeks during the trial and their Modified Melasma Area and Severity Index (MMASI) score were evaluated at 4, 8 and 12 weeks. The efficacy of the interventions were classified in four levels: complete response, significant response, partial response and no response.
Forty patients were enrolled in the study. At the end of the study (12 weeks), mean± standard deviation of MMASI score changed from 11.03±2.7 to 1.41±0.6 in the intervention group and from 11.25±2.9 to 2.37±1.2 in the placebo group, respectively (P Licorice extract can be used as a skin-lightening agent with minimal side effect in the treatment of melasma. Nano/micro solid lipid particles are used as carriers with unique properties like size, surface electrical bar. Moreover, a large amount of the drug might be loaded to increase the efficacy and decrease the adverse events.