The Olaplex No.0 Intensive Bond Building Hair Treatment is a professional-inspired treatment that primes your hair for absourbing nourishment. Features include:Repairs hair from chemical, thermal, technical, mechanical and environmental damageStrengthens hair bondsProtects hair structureUse as the first step in a two-part system with No.3 Hair Perfector to strengthen and repair all types of damaged hair.The Olaplex No.0 Intensive Bond Building Hair Treatment is a professional-inspired treatment with patent technology that repairs and strengthens all hair types.Key Benefits:Primes hair to absorb nourishment Repairs hair from chemical, thermal, mechanical and environmental changeStrengthens hair bondsProtects hair structureHow to use:On dry hair, saturate hair with No.0Leave on hair for 10 minutesFor best results, apply No.3 over the No.0 and leave for another 10 minutesRinse, shampoo with No.4 and condition with No.5