This best-selling Olaplex® Shampoo is now formulated to enhance the beauty of blonde hair. Olaplex® No.4-P Blonde Enhancer Toning Shampoo is sulphate free and strengthens, softens, and neutralises unwanted yellow brassy tones for brighter, more nourished hair. Olaplex® No.4-P maintains all the benefits of the original No.4 and contains just the right amount of tone to neutralise between salon visits. Olaplex® No.4-P Blonde Enhancer Toning Shampoo will help you to keep your colour bright.