The Kérastase Resistance Mask Therapist is formulated to address the needs of severely weakened hair, providing intensive repair and nourishment. This specialized hair mask works deep within the hair fiber to restore strength and reinforce structure, making hair more resilient to future damage. Regular use helps improve manageability and leaves the hair looking visibly healthier and revitalized. Ideal for integrating into a weekly deep conditioning routine to maintain long-term hair integrity.