BACKGROUND Red and blue light have beneficial, complementary effects on acne. OBJECTIVE To evaluate the efficacy and safety of at-home treatment of mild-to-moderate inflammatory acne with an investigational combination 660-nm red/415-nm blue light-emitting diode device (RBL) compared with a commercially available 415-nm blue light-emitting diode device (BL). MATERIALS AND METHODS This was an open-label randomized-controlled trial with a 30-subject goal ( n = 20 RBL, n = 10 BL). Subjects performed once-daily at-home treatments for 8 weeks, with 4-week (4W) and 8-week (8W) follow-ups. RESULTS Twenty-three subjects completed the study ( n = 14 RBL, n = 9 BL). Total lesions were significantly reduced at 4W ( p = .028) and 8W ( p = .015) with RBL but at neither timepoint with BL. Inflammatory lesions were significantly reduced at 4W ( p = .010 and p = .008) and 8W ( p = .005 and p = .02) with both RBL and BL, respectively. Noninflammatory lesion reduction was not significant in either group. No significant between-group difference in total, inflammatory, or noninflammatory lesion reduction occurred at any timepoint. Median investigator static global assessment was significantly lower with RBL at 8W ( p = .015). CONCLUSION Daily at-home treatment with RBL led to significantly reduced inflammatory and total acne lesions at 4W and 8W. Although equivalent to BL in most outcomes, RBL demonstrated a significantly greater reduction in median ISGA.
Friedmann et al. (2026) studied this question.