Similarly to serums for the skin, a hair serum is a very powerful formula for deep hair fiber repair. The Miracle Repair Serum creates a protective shield against all types of external aggressors (UV rays, salt, chlorine, sand, etc.), and it's also highly effective against the effects of heat. It provides protection for chemical treatments like coloring, bleaching, highlights, perms, and straightening. This serum is strongly recommended before any hair coloring or treatment, applied strand by strand.