Ultraviolet (UV) radiation is a major cause of photoaging 1 and photocarcinogenesis of both melanoma and non-melanoma skin cancers. 2 A variety of methods have been suggested to reduce UV-associated skin damages. 3 The World Health Organization (WHO) recommends limiting time of outdoor activities in the midday sun and keeping away from sun-reflective areas such as sand and snow to limit UV radiation to the skin. Sun protective barriers such as garments, sunglasses, hat, umbrella, and sunscreen are also recommended for UV protection. 4 Among all of these approaches, sunscreen is one of the most popular methods worldwide although the efficacy of different sunscreen types can vary drastically. Theoretically, sunscreens reduce UV-induced damage by forming a film or coating on the surface of stratum corneum that absorbs and/or scatters UV photons. Previous studies have reported factors which are affecting the efficacy of wearing sunscreen. Types of UV filters and adequately labeled sun protection