Olaplex No.4 Bond Maintenance Shampoo - 1L For all hair types, especially those needing clarifying or oil control. Olaplex No.4 Bond Maintenance Shampoo is a highly-nourishing and reparative shampoo. N°4 Shampoo repairs and protects hair from everyday stresses — including damaged hair, split ends, and frizz — by re-linking broken bonds. Leaves hair easier to manage, shinier and healthier with each use. N°4 is color-safe and proven to reduce breakage and strengthen all types of hair. Improves manageability and softness. Increases shine and leaves hair looking healthier. Helps prevent breakage and split ends. PH Balance: 6-6.5 Free of DEA, Aldehydes and Formaldehyde Use Dispense product into hands and emulsify. A little goes a long way.* Apply to wet hair, focusing on the scalp and working through to ends. Rinse well. For best results, follow with OLAPLEX Nº.5 Bond Maintenance® Conditioner.