Editor's TipEditor's Tip

For super sleek strands, apply Kérastase’s Fiber Architecte - Prime from ends up to roots before styling with your flatiron.

Kérastase

Birchbox Breakdown

It’s a vicious cycle: You decide to grow your hair out, only to see it break and split so disastrously that you’re forced to get a trim. With this reconstructive leave-in milk, however, you can kiss breakage goodbye and say hello to newly lustrous strands. Formulated with heat-activated ingredients, this treatment strengthens and protects the hair shaft from the damage caused by heat styling, ensuring that your hair grows out long and strong.

How to Use

Squeeze a dime-sized amount into hands and apply to towel-dried hair, starting from the ends and working your way to the roots. Gently detangle hair with a wide-toothed comb and style as usual.

Aqua/Water, Cyclopentasiloxane, Propylene Glycol, Dimethiconol, Triethanolamine, PEG/PPG-17/18 Dimethicone, Phenoxyethanol, Carbomer, Behentrimonium Chloride, Polyquaternium-4, Potato Starch Modified, Hydroxypropyl Guar, Methylparaben, Limonene, Amodimethicone, Cetyl Alcohol, Quaternium-87, Behentrimonium Methosulfate, Quaternium-33, Trideceth-6, 2-oleamido-1, 3 Octadecanediol, Geraniol, Linalool, Cetrimonium Chloride, Citral, Parfum/Fragrance

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Product Reviews & Sample Feedback

224 Reviews
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65
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17
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Most Helpful Customer Reviews

Finally!
Purchased

Have struggled with dry and damaged hair for a few years, after a horrible blonde highlighting. This product is the first to finally get my hair condition back in healthy shape! My hair is now so soft and silky, I want to touch it all the time. I put a small amount at the end of my hair and brush out after each wash. My ends look shiny and clean, and no longer look damaged. Love

5
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Top Notch Hair Product
Purchased

I love Kerastase products in general. This cream is applied before blow drying and doesn't leave a tacky feeling but protects your hair for daily styling. Dried hair feels fantastic.

5
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WOW- not what I remembered.
SampledPurchased

When I sampled this a couple years ago I remember absolutely loving it, so I have to say I'm really shocked at how awful this made my hair feel. I had just finished bleaching it, and after shampooing and doing a super deep conditioning treatment I put a little more than the recommended amount (not even double what your supposed to) in since my hair is pretty long and I just finished coloring it.. halfway through blow-drying I realized that I needed to shampoo it all out because the texture it was making my hair was just horrific. Soooo I tried again, and had the same problem with the texture. Plus this easily doubled my blow-drying time. Needless to say - I will be sadly returning this. Major let down.

1
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A must have!

I have been using this product for about 10 years and can say that it has helped my hair grow from being above my shoulders to by my waist now. I used to
blowdry and flat iron my hair every day and can say that this product helped keep my hair healthy.

5
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GREAT Product!

This product is amazing! I have been using it for years and it is great for protecting my thin/frizzy hair from heat. Very fresh and light scent!

5
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LOVE
Purchased

This brand has SAVED my hair and has made it soft, healthy and shiny. Worth every penny, I would definitely recommend this!

5
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Very good
Purchased

This product cuts down on my blow dry time. It keeps my ends moisturized for a few days (I go two-three in between washes) and it smells great. I havent been able to see long term effects yet but can't wait to keep using it.

4
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Amazing

This completely transformed my brittle, damaged hair in one use. It made my hair feel incredibly healthy and soft without weighing it down at all.

5
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Great Product

Have been using this for about a year. As others have said - it smells FABULOUS - very clean and light, not floral or "chemically." I use it in combination with Kerastas shampoos and masques and after about six months of use of this combo, my hair is in SIGNIFICANTLY better condition. I have fine straight hair and use a blow dryer and curling iron daily, so I am very prone to heat damage. Unlike others, I can't say that each time I style my hair looks or feels different than if I hadn't used it, but it absolutely has been part of improving my hair and its appearance over time by improving its overall condition and health.

5
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Amazing product
Purchased

This product has helped keep my color-treated hair feel like silk, even through daily blow-drys. Amazing, and well worthy the investment.

5
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