Red Light Phototherapy Alone Is Effective for Acne Vulgaris: Randomized, Single‐Blinded Clinical Trial

BACKGROUND Recently, a demand for safe and effective treatment of acne has been increasing. Although visible light has attracted attention as a new option, the effect of red light alone has not yet been evaluated. OBJECTIVES The objective was to assess the efficacy of red light phototherapy with a portable device in acne vulgaris. METHODS Twenty‐eight volunteers with mild to moderate acne were treated with portable red light–emitting devices in this split‐face randomized trial. The right or left side of the face was randomized to treatment side and phototherapy was performed for 15 minutes twice a day for 8 weeks. Clinical photographs, lesion counts, and a visual analog scale (VAS) were used to assess each side of the face at baseline and Weeks 1, 2, 4, and 8, and a split‐face comparison was performed. RESULTS The percent improvement in noninflammatory and inflammatory lesion counts of the treated side was significant compared to the control side (p