Retinol is almost always the answer to pretty much any skin issue — acne, fine lines, dark spots, drooping, dullness, dark circles, enlarged pores — you can think of. The best retinol cream or serum can help address all of the above concerns and improve your skin’s appearance with consistent use. The transformative ingredient is otherwise known as pure vitamin A. Along with a bunch of other vitamin-A derivatives starting with the letter R, retinol is an example of a retinoid — that’s the catchall term for these A-based formulas, both the over-the-counter (OTC) and prescription (Rx) varieties.