Chemical processes increase hair porosity, making it absorb up to three times more calcium from hard water than untreated hair. This calcium overload weakens hair from within and on the surface, leaving it dull and fragile. The Kérastase Première Bain Décalcifiant Réparateur is a decalcifying, repairing shampoo that gently removes calcium buildup while cleansing and restoring keratin links within the hair shaft, so hair feels stronger and more manageable from the very first wash.

Hard water deposits calcium on already porous, over-processed hair, compounding existing damage and leaving it limp, lifeless and dull. The Première Bain Décalcifiant Réparateur, a sulphate-free, professional-level shampoo, offers dual decalcifying and repairing action to fight this calcium overdose, repairing hair from the inside out while reducing breakage.

Damaged hair needs cleansing that repairs as it washes. The Première Bain Décalcifiant Réparateur is a white, creamy shampoo that transforms into a luxurious foam, gently cleansing the scalp and hair while removing calcium buildup. It leaves hair smooth, manageable, shiny and bouncy rather than stripped or weighed down.

Over-processing disrupts the hair's internal keratin bonds and increases its sensitivity to calcium absorption, which weakens the fibre further with every wash. The Concentré Décalcifiant Ultra-réparateur, a pre-shampoo treatment rich in pure acids, targets this root cause by rejoining fractured keratin bonds, fortifying strength and integrity from within.

Breakage in over-processed hair often stems from a build-up of calcium that weakens it internally and externally. The Kérastase Masque Filler Réparateur, with its opulent creamy consistency, penetrates deeply to deliver intensive conditioning, rebuilding the hair structure, refining the surface and significantly minimising future breakage.

Severely damaged hair benefits from a mask that goes beyond surface conditioning. The Masque Filler Réparateur is formulated for all damaged hair types and works to reinforce internal strength and protect against future breakage, leaving hair visibly stronger and more beautiful, particularly after chemical treatments.

Bleaching increases porosity, leading to excess calcium absorption that weakens hair internally and dulls its appearance. The Masque Filler Réparateur penetrates deeply into the hair to maximise recovery and conditioning care, acting as a true hair saviour to restore hair to its healthiest, strongest and most beautiful condition.

Damaged hair is more prone to frizz because its compromised surface struggles to repel humidity. The Kérastase Première Sérum Filler Fondamental is a lightweight, repairing anti-frizz serum that seals the cuticles and locks out frizz while deeply nourishing the fibre, leaving hair smooth and supple.

Frequent heat styling weakens already fragile hair further. The Sérum Filler Fondamental protects hair against heat tools up to 230°C while filling the fibre surface with matter to recreate softer, smoother hair, helping shield it from daily styling damage.

Damaged or over-processed hair has heightened porosity, causing it to absorb up to three times more calcium from water than untreated hair, resulting in calcium overdose both internally and externally. The Sérum Filler Fondamental offers a dual-action solution, its lightweight balm-like texture sealing the cuticles while replenishing the fibre and reinforcing strength.

Hair weakened by calcium overload and humidity often becomes difficult to style. The Sérum Filler Fondamental provides dual-action care, sealing the hair's surface while reinforcing it from within, so hair becomes smooth, supple, easy to style and effortlessly manageable.

Before shampooing, the Concentré Décalcifiant Ultra-réparateur, rich in pure acids, removes excess calcium buildup and begins repairing hair from the inside out. With its transparent gel-like texture, it rejoins fractured keratin bonds, leaving hair stronger and appearing healthier and glossier, as if renewed, right from the start of the routine.

Hard water contains calcium that fragile, dry, over-processed or bleached hair absorbs at a much higher rate due to its increased porosity, amplifying existing damage. The Kérastase Concentré Décalcifiant Ultra-réparateur is a pre-shampoo treatment designed to counter this, removing calcium buildup from the hair while repairing it from the inside out, restoring strength and rejuvenating its stiff, lacklustre appearance.

Repair at the structural level depends on rejoining the keratin bonds within the hair fibre that damage breaks apart. Across the Kérastase Première range, from the Bain Décalcifiant Réparateur shampoo to the Concentré Décalcifiant Ultra-réparateur, formulas work to restore keratin links and repair hair at the core, improving overall strength rather than offering only surface conditioning.

A complete routine for damaged hair should address calcium removal, internal repair and surface protection together. Begin with the Concentré Décalcifiant Ultra-réparateur pre-shampoo treatment, follow with the sulphate-free Première Bain Décalcifiant Réparateur shampoo, use the Masque Filler Réparateur weekly for intensive repair, and finish with the Sérum Filler Fondamental daily to protect against humidity and heat up to 230°C, progressively restoring strength, smoothness and shine over time.