Researchers compared the biosafety and therapeutic efficacy of five retinoids for antiphotoaging therapy, according to a recent study published by Shu et al in Photochemistry and Photobiology. They analyzed the outcomes of treatment with retinol, retinol acetate, retinol propionate, retinol palmitate, and hydroxypinacolone retinoate—with the goal of determining the optimal retinoid for antiphotoaging therapy in vitro and in vivo. The researchers found that 5 μg/mL of retinol, retinol propionate, retinol palmitate, and hydroxypinacolone retinoate had positive antiphotoaging, antioxidative, anti-inflammatory, and anti–extracellular matrix degradation activity in vitro. Further, when administering the retinoids in ultraviolet B–induced mice, 5 mg/kg of topical retinol propionate and retinol palmitate were shown to be superior to retinol and hydroxypinacolone retinoate. The researchers hope their new findings can lead to the next steps in the clinical application of retinoids in patients with skin photoaging.