Kérastase Serum Thérapiste is a reconstructive two-stage leave-in serum for severely to very severely damaged hair that repairs the hair fibres and seals the tips. The 2-phase texture of oil and cream protects the hair from heat up to 230°C and significantly shortens the blow-drying time. Hair looks smoother, shinier and healthier. Application After shampooing, work into the towel-wet lengths and ends. Do not flush.