Evaluation of the efficacy of a sunscreen containing ultra‐long UVA1 and other UVR broad‐spectrum filters on skin barrier protection and melanin content reduction in Chinese adults: A single‐center study

Abstract Background and Aims The protection for ultra‐long UVA1 is lacked in the market, posing potential damage from ultra‐long UVA1 irradiation. The study aims to evaluate the efficacy of a sunscreen containing multiple components, especially Mexoryl® 400 for improving skin barrier function and reducing melanin content. Methods This single‐center study included adults with sensitive and normal skin in China in November 2022. Participants received the test sunscreen for 4 weeks. Melanin and hemoglobin content, sebum secretion skin hydration, and trans‐epidermal water loss were evaluated at T0d, T7d, and T28d. The self‐assessment was done at T15min, T7d, and T28d. Results Sixty participants were included, including 30 self‐claimed sensitive skin in the sunscreen group. The sunscreen demonstrated significant improvements in skin parameters. Skin redness reduced by 9.84% at T28d, sebum content in the forehead area decreased by 22.70% at T28d, and skin stratum corneum hydration increased by 38.44% at T28d, p < 0.001 respectively. Most notably, skin melanin content significantly reduced by 13.49% after 4 weeks' usage ( p < 0.001). No adverse reactions were reported in either group. Conclusions The study sunscreen improved the skin condition by decreasing the melanin content, regulating skin barrier function, and achieving a balance of skin hydration and sebum secretion.