It rebuilds hair bonds, strengthens and protects hair integrity. Use as the first step in a two-part system with N°.3 Hair Perfector. The Nº.4P Blonde Enhancer Toning Shampoo, infused with patented OLAPLEX Bond Building Technology, is a highly concentrated purple shampoo that cleanses, tones and repairs with a sulfate-free formula that neutralizes brassiness and boosts brightness after just one use.
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