Details: Hair is made up of protein. Every touch, every treatment, every style you love—it all rewrites your hair’s protein. When protein is damaged, hair’s look and feel is compromised. That’s why Nexxus uses protein science not just to repair hair but to restore its ability to perform. It isn't about one perfect hair day. It's about a lifetime of healthy hair, built strand by strand. Frequent heat styling and chemical processing can break down disulfide bonds and strip essential amino acids, leading to cuticle erosion and damage deep within the hair fiber. This makes strands weak, dull, tangled, harder to style, and less smooth and shiny. KERAPHIX, our extreme damage repair collection, is powered by KRT Keratin Resistance Therapy with liquid crystal serine amino acid to rebuild internal strength from inside out. Repair and resist visible damage from coloring, bleaching, highlighting, styling, heat and more with 24X stronger hair restored to be as strong as virgin hair. This conditioner for damaged hair targets surface damage where it is needed most while providing deep moisture to revive dry, brittle strands. KRT technology seals the outer layer to restore elasticity—so hair is shiny, feels soft, resilient, and ready to bounce back with every style. Nexxus, the protein science behind powerful hair since 1979. System vs. non-conditioning shampoo Based on a breakage study on bleached treated hair with Keraphix Shampoo & Conditioner + Treatment vs. virgin hair.