IRCT201403109014N31 IRCT 2014-03-25 Vice-chancellor for Research the Technology, Hamadan University of Medical Sciences Comparison of the efficacy and tolerability of adapalene gel 0.1% versus tretinoin gel 0.05% in patients with mild to moderate acne vulgaris Comparison of the efficacy and tolerability of adapalene gel 0.1% versus tretinoin gel 0.05% in patients with mild to moderate acne vulgaris: a double blinded randomized clinical trial 1991-12-01 anticipated 48 Complete https://irct.ir/trial/9470 interventional Randomization: Randomized, Blinding: Double blinded, Placebo: Used, Assignment: Parallel, Purpose: Treatment, Other design features: Randomization: 48 cans of the same color and size including 24 cans have adapalene gel 0.1% and 24 cans have tretinoin gel 0.05% will be numbered and then will be given to the patients at random. Blinding: The patients will receive cans with the same shape but different content. Thus, they will not aware of the intervention. Furthermore, the physician who will examine the patients will not be aware of the intervention. Thus, the design of the study will be double blinded. 2 Acne vulgaris. Intervention 1: Rubbing adapalene gel 0.1% on the area of facial acne lesion once a day for 12 weeks. Intervention 2: Rubbing tretinoin gel 0.05% on the area of facial acne lesion once a day for 12 weeks.