Photoprotection Efficacy of Sun Protection Factor and Iron Oxide Formulations in Diverse Skin With Melasma and...

Visible light (400-700nm) comprises 45% of the sunlight spectrum and can induce both immediate and persistent skin darkening, as well as worsen dyschromia, especially in the skin of color population. In a recent mini-zone study, we demonstrated that iron oxide (FeO)-containing formulations could protect skin from visible light-induced pigmentation in Fitzpatrick skin type (FST) IV individuals, while ultraviolet (UV) protection sunscreen SPF 50+ (sun protection factor) could not. To assess the benefit of adding FeO-containing foundation into real-life daily sun care routine in improving the appearance of photodamage and melasma, we evaluated the efficacy of two sun protection regimens (SPF50 alone and SPF50+FeO) in healthy women of FST III to VI for 12 weeks. Clinical evaluation and colorimetric measurement showed that both regimens significantly improved skin quality and overall appearance over 12 weeks compared to baseline. At week 4, the photodamage subgroup using SPF50+FeO showed early improvement over baseline in skin roughness (visual and tactile). The melasma subgroup using SPF50+FeO showed early improvement in overall healthy appearance. At week 12, although both groups showed improvement in colorimetric measurements (L*), the response was different: 36% of melasma participants in the SPF50+FeO group showed superior improvement in their skin radiance (L*) vs 0% in the SPF50 group. A self-assessment questionnaire revealed that SPF50+FeO enhanced the quality of life in participants with melasma. This study demonstrated the importance of including visible light protection into a daily sun care routine, especially for melasma: masking and improving existing conditions indoors and outdoors at the same time. J Drugs Dermatol. 2025;24(7):662-667. doi:10.36849/JDD.9240.