Kérastase’s first pre-shampoo hair treatment, suitable for all hair types, removes excess calcium and helps visibly repair all types of damaged hair. This includes damage by heat tools, colour treatment, bleaching, over-processing and other types of hair damage. Calcium in water can further damage already delicate over-processed or bleached hair. Being more porous, damaged hair can absorb up to 3 times more calcium than natural hair. This hair treatment is formulated with a concentration of pure citric acid and glycine and has a dual action: it decalcifies hair from this calcium overdose and works to repair its appearance, helping to visibly restore hair strength and reverse its stiff, dull appearance. Once excess calcium is removed, this product which is formulated with the amino acid glycine, works to deeply repair the feel of strands. Hair is left stronger, healthier-looking, and shinier – as if renewed.