COSRX Retinol 0.5COSRX Retinol 0. 5 exists now, it suggests a retinol product with a concentration of 0. 5%. Retinol is a derivative of vitamin A and is a well known and effective ingredient in skincare. It is a type of retinoid and is praised for its ability to promote skin cell turnover, stimulate collagen production, and improve the appearance of fine lines, wrinkles, and uneven skin tone. When using retinol products, it's essential to introduce them into your