Use as the first step in a two-part at-home system with No. 3 Hair Perfector to strengthen and repair all types of damaged hair. No. 0 Intensive Bond Building Hair Treatment contains the highest concentration of the patented bond building technology of any Olaplex at home product. Olaplex products feature first-of-their-kind patented bond-building technology which relinks the broken disulfide bonds caused by chemical thermal and mechanical damage to the hair. This formula is made to work with every hair type providing real structural repair that works from within.