OLAPLEX No.0 Intensive Bond Building Treatment is a professional-inspired treatment that primes your hair for deeper repair, rebuilds hair bonds, strengthens, and protects hair integrity. Redesigned for a quick and targeted stream application, this treatment features an easy-to-use nozzle that primes the hair and delivers the highest concentration of the patented bond-building technology of any Olaplex at-home product. Use this as the first step in a two-part at-home system with No.3 Hair Perfector (sold separately) to strengthen and repair all types of damaged hair.