Great repair calls for great prep. Taking inspiration from professional treatments, Olaplex’s No. 0 is a primer for No. 3 which ensures maximum nourishment absorption for deeper repair. Boasting the highest concentration of the patented Olaplex technology in any take-home formula from the brand, the No. 0 Intensive Bond Building Treatment magnifies the performance of the No. 3 Hair Perfector, helping rebuild bonds, boost overall strength and protect hair integrity. Scientifically Proven Results: 68% more repair and 3x stronger hair*. This bottle should last about 3-6 applications depending on hair length and density. Suitable for all hair types; ideal for those with visible hair damage. pH-balanced. Vegan-friendly. Cruelty-free. Does not contain phthalates, parabens, sulfates, gluten, phosphate or nuts. Ingredients Water (Aqua), Bis-Aminopropyl Diglycol Dimaleate, Sodium Benzoate, Phenoxyethanol