Olaplex No.4 Bond Maintenance Shampoo 20ml This #1 best-selling prestige shampoo* strengthens and reinforces bonds for more resilient hair, at a molecular level. The luxuriously nourishing and abundant lather gently cleanses and replenishes hydration– never stripping essential moisture– leaving hair soft and lightweight. Clinically proven to boost shine and reduce split ends and frizz. Formulated for straight, wavy, curly, and coily hair types with medium to coarse textures – plus all porosity levels.