Olaplex No.4P Blonde Enhancer Toning Shampoo is a highly concentrated shampoo that cleanses tones and repairs hair fiber while hydrating from roots to ends. This Sulfate-free formula strengthens, softens, and neutralizes yellow tones for brighter, more manageable hair. This highly concentrated, rich lather allows for customizable toning, the longer you treaty, the brighter the results. Olaplex for blonde hair  helps neutralize brassiness and boost brightness for your best blonde hair yet.