All RepHair products are sulfate, silicone, paraben and petrochemical free, made with natural and organic ingredients and AC-11®. Rephair is a four product combination treatment system for your hair similiar to how Proactiv® is a combination treatment program for your skin, each product works in conjunction with one another. The Shampoo allows the AC-11® to work on the scalp, the Conditioner allows the AC-11® to work on restoring split ends and the Spray both detangles and volumizes while allowing AC-11® to penetrate the hair shaft for the entire day. The mask, used once or twice a week allows AC-11® to repair weakened and damaged hair strands due to salon treatments and enviormental factors. You will notice results within the first week of use! What is AC-11®?