Kérastase has identified the cause of recurring hair damage: Calcium!
Damaged hair is more porous and absorbs up to three times more calcium from water than healthy hair. As a result, calcium builds up inside the hair.
With every contact with water, calcium deposits on the hair, causing lasting damage. It penetrates the keratin chains and breaks their bonds, leaving hair stiff, unmanageable, and prone to breakage. On the surface, calcium accumulates on the cuticle scales, making hair rough and dull.