A vitamin A derivative, retinoids work by increasing collagen production as well as increasing the rate of skin cell turnover of keratinocytes (cells on the outermost layer of our skin. RETINOL AND ACNE Retinol or retinol derivatives such as Tretinoin, Tazarotene, Isotretinoin help treat acute acne and also decrease pore size. OTC formulas like Retinyl...