Kérastase discovered the reason behind damage that keeps coming back: CALCIUM!

3X

More calcium is absorbed with damaged hair as it is more porous (vs healthy hair), leading to a calcium overdose

PERSISTENT

Damage happens when calcium sneaks in-between keratin chains at every contact with water, breaking their links, making hair rigid, stiff and easy to break

BUILD-UP

Of calcium on the outside makes hair rough and dull