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The Effects of Calcium Buildup on Damaged Hair

Most of us will be aware of the benefits calcium can have on our bone health, muscle activity, and heart and nerve function, but a calcium buildup on hair is anything but beneficial. Calcium deposits on hair can be particularly detrimental to lightened, coloured or chemically treated hair, exacerbating pre-existing damage and making strands feel dry, dull and brittle. In the below guide, Kérastase hair care experts identify the effects of calcium on damaged hair and share their insights into removing calcium buildup and enhancing your hair’s strength with revolutionary formulas from the new Kérastase’ Première decalcifying collection.

Calcium buildup on hair

The biggest culprit for a buildup of calcium deposits on the hair comes from exposure to hard water, but you’re more likely to notice its effects if your hair is lightened, dyed, chemically treated or heat damaged. ‘Hard water’ refers to a heavy amount of minerals (like calcium) found in tap and shower water. Depending on where you live or travel, hard water can be difficult to avoid.
Water damage to hair and scalp can happen gradually, making it difficult to recognise. Below, we have included common warning signs to tell if your hair is damaged from a calcium buildup through regular hard water exposure.
• Dry/coarse texture
• Brittle/prone to breakage
• Dull and lacking in shine
• Difficult to manage
• Colour fading
• More tangling
• Thinning hair
• Residue on scalp and hair

How calcium buildup can worsen damaged hair

Every individual hair is composed of the ‘root’ and the ‘shaft’, the shaft being the visible part of the hair. The shaft contains an exterior shell – the cuticle – and an internal segment – the cortex. We can think of the cortex as the heart of the hair shaft, and it is rich in proteins, including keratins. Keratin is made up of multiple chains, and it’s responsible for our hair’s strength and resistance. When heat or bleach is applied to the hair, it can disrupt the structure of the keratin and break the links between chains.
Calcium alone isn’t the cause of damage; the hair’s keratin chains are already broken and vulnerable. Chemical processes make the hair’s surface more porous and rifer for calcium absorption. So, how exactly is calcium in water bad for your hair? Calcium can leave a residue on the scalp and hair shafts that make it tough for products to penetrate, cleanse and moisturise the hair, preventing damaged hair from repairing and returning to natural health.

How to remove calcium buildup on hair in 3 steps

Kérastase was founded on the ethos of hair health and personalised hair care, and our new Première range has been specifically formulated to remove calcium deposits on scalp and hair and recreate up to 99% of hair’s original strength. Suitable for all hair types, our six-product hair care system is infused with an 8% pure concentrated blend of citric acid and glycine to penetrate inside the hair fibre and decalcify tresses.
Citric acid acts from the hair surface to core to eliminate calcium overdose, thus neutralising its trademark dullness and stiffness. Glycine (an amino acid) penetrates the inner layers of the hair to reconnect broken keratin links to reinforce up to 97% of the hair’s inner structure. Below, discover how you can use this dual-action system to repair damaged hair at home.

Premiere Pre Shampoo squeezed into hand

1. Activate and cleanse

This first step in our damaged hair care routine is to activate with Première Pre-Shampoo Treatment and cleanse with Première Repairing Hair Shampoo – our decalcifying repairing shampoo.

1.    Apply Première Pre-Shampoo Treatment for Damaged Hair generously to wet ends before shampooing. Do not rinse and leave on for 5 minutes. 

How it works: this decalcifying treatment helps repair broken links between keratin chains, reverses stiffness and dullness and generates 75% more shine.*

2.    After 5 minutes, layer Première Decalcifying & Repairing Hair Shampoo onto your wet hair. Massage and emulsify. Rinse thoroughly. Layering is the key to unlocking maximum results in the first stage of this hair care routine.

How it works: this shampoo dramatically repairs hair at the core for 93% stronger tresses** that feel renewed and look shinier.

*Instrumental test after application of the Concentré Décalcifiant Ultra-Réparateur

**Instrumental test after application of Bain Décalcifiant Rénovateur

2. Treat

Next up in our damaged hair repair system is to treat the hair with Première Repairing Conditioner for Damaged Hair and Première Repairing Hair Mask. For thick hair, use the Première Repairing Hair Mask in place of conditioner whenever your strands need a boost. For thin hair, use the two layered together once per week.

1.    Apply Fondant Première Repairing Conditioner to shampooed, towel-dried hair. Massage through lengths and ends. Leave on for 3-5 minutes, then rinse.

How it works: this lightweight, anti-rigidity formula instantly restores moisture and fluidity, helping to strengthen hair and stop hair breakage. Hair is more supple, twice as soft, 7 times smoother*, 82% shinier* and has 86% more moisture.**

2. After conditioning, massage the Première Repairing Hair Mask through lengths and ends. Leave on for 5 minutes, then rinse.

How it works: as an anti-breakage repair mask, this product fills hair surface and intensely penetrates fibre to rebuild inner strength and encourage recovery in damaged hair. Enjoy 98%*** less breakage and 97% inner structure reinforcement.****

*Instrumental test after application of Fondant Fluidité Réparateur

**Instrumental test after application of the Bain Décalcifiant Rénovateur + Fondant Fluidité Réparateur

***Instrumental test after application of the Masque Filler Réparateur + Bain Décalcifiant

****Instrumental test after application of the Concentré Décalcifiant + Bain Décalcifiant + Masque Filler

3. Finish

Finish your hair care treatment with Première Intensive Repairing Serum and Première Repairing Hair Oil.

1.    Apply Première Intensive Repairing Serum to towel-dried hair. This is a leave-in serum, so you can blow-dry and heat style after application.


How it works: this is a repairing, anti-frizz filler serum that fills hair surface to create softer, smoother hair. Combats humidity and deeply nourishes locks, while protecting from heat up to 230°C* so hair is 99% stronger.* Has 72-hour anti-frizz* properties.

2.    Première Repairing Hair Oil is suitable for use on either damp or dry hair. Apply 1 or 2 pipettes to hair, leave in, and style.

How it works: formulated to provide intensive shine, this repairing oil seals split ends (up to 92%) and amplifies shine up to four times.**


*Instrumental test after 1 application of the Sérum Filler Fondamental

**Instrumental test after application of the Huile Gloss Réparatrice

Now that you have an insight into how calcium buildup on hair can damage strands, explore our tips for maintaining coloured hair.

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