Vitamin A derivatives—like the retinol in this serum—are the superstars of skincare. Piles of research prove that these ingredients smooth roughness, fade discoloration and build new collagen to soften lines and improve laxity (in other words, reverse all of the damage done before your religious sunscreen use). Apply a thin layer of this silky serum before bed (sunlight can deactivate retinol); layer a moisturizer on top if you have dry skin.
$15, Target.com
