Olaplex No. 4P Blonde Enhancer Toning Shampoo is a sulfate-free purple shampoo that tones, brightens, and strengthens blonde, lightened, or grey hair. Infused with patented Bond Building Technology™, it neutralizes unwanted yellow tones while enhancing softness and manageability. This deeply nourishing formula repairs and protects hair from damage while restoring vibrancy and shine. Ideal for color-treated and chemically processed hair, it delivers hydration without stripping moisture, helping maintain salon-fresh tones. Suitable for regular use, it leaves hair visibly brighter and healthier.