A Randomized Controlled Trial Analyzing the Likeability, Usability, and In-Use Efficacy of Mineral Sunscreens Across...

Mineral sunscreens are increasingly favorable among consumers. However, mineral sunscreens typically cause a white cast that can impact consumer selection and application.

This study measured the whitening effect of mineral sunscreens across diverse skin tones and evaluated its relationship with consumer perception, application behavior, and the product's efficacy in terms of ultraviolet A protection factor (UVAPF) and sun protection factor (SPF).

Five mineral sunscreens with differing whiteness and one chemical sunscreen were applied at 2 mg/cm2 on the forearm. Two of the 6 sunscreens were randomly assigned for uncontrolled application on the lower legs, and the participants' preferred product of the pair was then applied to the face at his/her discretion. Imaging and Hybrid Diffuse Reflectance Spectroscopy (HDRS) of the arm and face determined UVAPF and SPF.

Controlled application with all mineral sunscreens led to significant whitening, which was 3 times more pronounced on darker skin tones. Uncontrolled sunscreen application showed a significant reduction in the amount applied, whitening, and sunscreen efficacy. Participants had reduced preference for more whitening sunscreens and selected sunscreens in product pairings that resulted in less whitening.

Patients may avoid sunscreens with negative whitening aesthetics or compensate with reduced application, compromising their ability to achieve appropriate sun protection, especially in darker skin tones.  .