Olaplex Blonde Enhancer Toning Shampoo No.4P is a highly concentrated purple shampoo which brightens your blonde and neutralizes brassiness after one use. It is formulated with Olaplex’s patented bond building technology that is intensely hydrating and reparative. Olaplex have really cracked the code with this combo! This best-selling shampoo allows you to control the toning level. The longer you leave it in the brighter your results!