On my retinol “off” days I really enjoy using the Sunday Riley Good Genes lactic acid serum to give my skin a glowy boost. Lactic acid helps peel away that dull layer of skin making way for a brighter and healthier layer. This helps make my skin more receptive to my products and helps ensure better penetration. Another AHA favorite of mine is Drunk Elephant's Framboos Glycolic Night Serum.