Olaplex No.0 Intensive Bond Building Treatment is a professional-inspired, in-home system designed to intensely repair and strengthen damaged hair. It works by relinking broken bonds within the hair structure, making hair look and feel significantly stronger and healthier. This product is best used as the first step in a two-part system, followed by the No.3 Hair Perfector, to provide the highest concentration of Olaplex patented technology. It is suitable for all hair types, especially those experiencing damage from chemical processing, heat styling, or daily wear and tear.