Kérastase Masque Thérapiste is a rich, repairing hair treatment for very damaged, over-processed hair - Ideal for thick hair. The unique butter texture envelops hair fibre with a repairing blend to act as a bandage for a nourished, healthy result. Erosion Levels 3-4. Key Ingredients: FIBRA-KAP™ (Keratin Associated Proteins) - KAP make up 50-60% of hair's structure. When hair is damaged, these proteins are lost. Fibra-KAP is a powerful complex to restore missing proteins and restore strength to hair fibre Sève de Résurrection