Each product in the Wella Professionals Ultimate Repair range is infused with AHA (Alpha Hydroxy Acid) and Omega-9. The AHA is small enough to penetrate the hair fibre, working at the deepest level to support the internal bonds. Meanwhile, Omega-9, a nourishing fatty acid, fills and smooths the outer layer of the hair cuticle, so you get inside-out repair that leaves strands more resilient.