Product Details This is a Beyond Beauty product which means it has been sourced tried and tested and finally declared one of the most new and innovative heroes out there. This professional-inspired No. 0 Intensive Bond Building Hair Treatment from OLAPLEX primes your hair for deeper repair rebuilds hair bonds strengthens and protects hair integrity. 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. How To Use Apply No.0 to dry hair fully saturating each section. Let process for 10 minutes. Do not rinse. Apply No.3 Hair Perfector over hair with No.0 applied to it combing through as needed. Let process for a minimum of 10 minutes. Rinse shampoo and condition. For best results use No.4 Shampoo and No.5 Conditioner. Use the two-part system once a week or two to three times a week for damaged hair. Full Ingredients Water (aqua) bis-aminopropyl diglycol dimaleate sodium benzoate phenoxyethanol