Background: Melasma is a common acquired hypermelanosis in areas exposed to sunlight, which exacerbates with sunlight, pregnancy, and endocrine diseases. Melasma is problematic regarding cosmetic especially in women. Many drugs have been used for its treatment, but regarding side effects, they have limited relative usage. Therefore, testing a new drug with higher effectiveness and fewer side effects is necessary. This study attempted to evaluate the effectiveness of kojic acid on melasma Methods: In this study double-blind clinical trial study, 40 patients with melasma were enroled. One group of 20 people received kojic acid cream 2%, and the other used glycolic acid 10% and hydroquinone cream 2%. In the first group, 43 pigmented macules and in the second group, 21 pigmented macules existed. The changes of pigments in terms of recovery time, color tone and size of the pigments over a three-month treatment period was evaluated with clinical assessment, completing monthly questionnaire, and in a few cases with the aid of Wood’s lamp. After the three-month treatment period, the collected data using the Friedman test, t-test were analyzed Findings: In total, 79% of the patients were cured after 3 months. According to Friedman test, regarding healing time of the pigment, there was a significant difference between the groups (P=0.008). Regarding the color tone changes of the pigment at the end of the second and third months, there was a significant difference between the two groups Conclousion: Kojic acid 2% cream has a good efficacy in the treatment of melasma with no serious complications
