Olaplex No.4 Bond Maintenance 250Ml Shampoo (2023) Olaplex Bond Maintenance No. 4 Shampoo. Olaplex brand formulas look for broken bonds in the hair (which are caused by chemical, thermal and mechanical damage) and repair them, restoring the hair. Bond Maintenance Shampoo No. 4 repairs ends while gently cleansing hair, providing deep hydration and strength. This fourth step of the Olaplex protocol is formulated with proprietary Olaplex bridge reconstruction technology. Allows to repair disulfide bonds while gently cleansing hair. Restores strength and flexibility with each wash and provides hydration and shine to hair that has been colored or bleached. Strengthens and nourishes all types of hair.