Olaplex No.0 Intensive Bond Building Treatment - 155ml For all hair types, especially for those with visible damage. The No.0 Intensive Bond Building Hair Treatment primes hair for max repair. It 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 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. Free of DEA, Aldehydes and Formaldehyde Use Apply to dry hair, fully saturating each section. Use the two-part system with N°.3 once a week or two to three times a week for damaged hair.