Our patented OLAPLEX Bond Building Technology™ is in every step of the complete hair repair system. Learn how it repairs damage in all hair types on a molecular level. What makes healthy hair dull, discolored, dry, unmanageable, or oily? Buildup. Nº.4C Bond Maintenance® Clarifying Shampoo is new technology to reveal your healthiest hair. Optimize your hair repair results by removing more impurities that damage hair. Harsh clarifiers can leave hair like straw. Nº.4C is sulfate-free & pH balanced to maintain hydrated hair.