Primes Hair For Max Repair. The No.0 Intensive Bond Building Hair Treatment Has Been Redesigned For A Quick And Targeted Stream Application, With 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. To Strengthen And Repair All Types Of Damaged Hair, Use As The First Step In A Two-Part At-Home System With No.3 Hair Perfector (Sold Separately). Ingredients: Water (Aqua/Eau), Bis-Aminopropyl Diglycol Dimaleate, Phenoxyethanol, Sodium Benzoate How To Use: Apply To Dry Hair, Saturating Each Section Thoroughly And Evenly From Root To Tip. Spray The Liquid Into The Hair In Small Sections, Allowing It To Be Fully Absorbed As You Go. Saturate Lightly. Hair Should Be Damp But Not Soaked. Allow For A 10-Minute Processing Time. Do Not Rinse. Use The Two-Part System With N°.3 Once A Week Or Two To Three Times A Week For Damaged Hair.