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. With a Broad Spectrum Clarifying System and scientifically proven OLAPLEX Bond Building Technology. Benefits: Airy volume & softness. Restored shine. Vibrant color clarity. Deeply clean scalp. **OLAPLEX products are thoroughly tested in-house and by independent third-party laboratories for safety and efficacy. This product testing includes the industry standard Human Repeat Insult Patch Test (HRIPT), which tests for skin irritation or sensitivity. All of OLAPLEX products passed the HRIPT, meaning the products show no signs of causing irritation, inflammation, or sensitivity. **