OLAPLEX No.4 Bond Maintenance Shampoo is a highly moisturizing, reparative shampoo that leaves hair easy to manage, shiny, and healthier with each use. No.4 is color-safe and proven to reduce breakage and strengthen all types of hair. Repairs and maintains bonds within the hair Eliminates frizz and flyaways Reduces breakage For all hair types PH Balance: 6-6.5 Allure 2022 Readers' Choice Award Winner OLAPLEX products are thoroughly tested in accordance with industry standards in-house and by independent third-party laboratories for safety and efficacy Key Ingredients Bis-Aminopropyl Diglycol Dimaleate- Patented bond building technology that rebuilds broken and weakened bonds