How Do Five Retinoids Really Stack Up Against Each Other?

Five retinoids including retinol (ROL), retinol acetate (RAc), retinol propionate (RP), retinol palmitate (RPalm), and hydroxypinacolone retinoate (HPR) can help treat skin photoaging, but little was known about how they compare to one another.

Now, a new study in Photochemistry and Photobiology compares retinoid types for anti-photoaging therapy both in vitro and in vivo.

Four retinoids (RPalm, RP, HPR and ROL) but not RAc were effective for anti-photoaging treatment at 5 μg/mL in vitro, with action mechanisms associated with antioxidative, anti-inflammatory and anti-skin extracellular matrix (ECM) degradation activities. Notably, both RPalm and RP appeared superior to HPR and ROL for those activities. Importantly, both RPalm and RP were shown to be optimal for anti-photoaging therapy when topically applied at 5 mg/kg in a UltravioletB-induced mice model of photoaging, which is consistent with their high anti-photoaging activities in vitro. Additionally, topical application of these five retinoids showed satisfactory biosafety without causing significant apoptosis in animal organs, although RP application led to a slight decline in animal body weights. 

Collectively, these data have laid a good foundation for the next development of the clinical application of these retinoids for skin healthcare, the study authors conclude.