Objective. Recurrent aphthous stomatitis (RAS) is a common oral mucosal disease, yet effective therapeutic approaches are lacking. This study aimed to determine the effects of application of berberine gelatin in the treatment of minor RAS (MiRAS). Methods. A randomized, double-blind, placebo-controlled, clinical trial was performed. The gelatin containing berberine (5 mg/g) or vehicle only was applied 4 times per day for 5 days. Clinical evaluation included pain level, size, erythema, and exudation of certain ulcers on days 1, 2, 4, and 6. Results. A total of 84 subjects fulfilled the study wi...