Strengthen your extremely damaged & sensitised hair with the Schwarzkopf Professional BC Bonacure Fibre Force Fortifying Mask, a recharging weekly mask. When hair is severely over-processed, brittle & broken, it needs to be refortified. This intense, rich cream does just that, working to restore hair fibres & replenish cell bonding with keratin, while strengthening the Cell Membrane Complex. Used once a week, it gives your hair a real boost of energy, helping to detangle & improve combability, while perfectly sealing the hair surface. Work into towel-dried hair & rinse out after 5-10 minutes.