The Olaplex No. 4P Blonde Enhancer Toning Shampoo is a highly concentrated purple shampoo that cleanses, tones, and repairs hair. It neutralizes unwanted brassy yellow tones while keeping hair hydrated from root to tip. This formula is designed to brighten blonde, lightened, and gray hair. It reinforces the hair bonds to maintain health and vibrancy, ensuring a salon-quality finish between professional treatments.