Kerastase Education Manager Joaly Alcala explained that 50 percent of hair is made up of tiny proteins that link and bond keratin together in the hair called KAPs (keratin associated proteins). When you undergo longterm coloring (like me!) or other demanding chemical processes, these proteins eventually disappear and cause hair structure to collapse.

According to Joaly, L'Oréal scientists found a way to synthetically add the KAPs that were lost forever back into the hair, and this new line is the result. The products include sap from a rare climbing plant that grows in the world’s most arid regions and has the unique ability to come back to life, even after 10 years of near death.

"We are literally giving hair a second life, bringing it back to its lustrous beginnings, and at incredible speeds," Joaly told me.

As a fitness editor, I rarely wash my thick hair at home, so I had to get used to toting around a bunch of products rather than using whatever is at the gym. For eight weeks, I used the shampoo and conditioner three times a week, and I used the leave-in serum and masque once a week.

Bain Thérapiste: Out of all four of the products, I was most shocked by the shampoo's immediate results. I was incredibly surprised by what a huge difference the shampoo made in my hair's texture after a single use — my hair felt smoother even as I was showering in SoulCycle's locker room! I will say that this shampoo is much more concentrated and has more of a glue-like texture than any product I've ever tried. A little went a long way, even on my superthick hair.

Soin Premier Conditioner Thérapiste: The scent was delicately floral, but the texture of this conditioner was a little thinner than I had anticipated. This was not a thick conditioner by any means, but the combination of this step followed by the shampoo was an incredibly reparative process. I had to get used to conditioning my hair before shampooing, but the switch left my hair feeling smoother, bouncier, and lighter than I had anticipated. I didn't realize how much my other conditioners had been weighing my hair down.

Masque Thérapiste: This thick and creamy masque had a light, floral scent and a texture that reminded me of whipped body butter. I hung out in the shower with it on for about 10 minutes and was incredibly surprised by how shiny and smooth my hair was after each use. I will definitely continue to use this product for months to come.

Serum Thérapiste: I have very little breakage at my ends and didn't notice as dramatic a difference in my hair as I did from using the other products. I will say that compared to other serums I've used in the past, this one felt incredibly light and didn't weigh my hair down or make it feel oily.

Over the last two months, my regular flyaways and static at the part of my hair have been nearly eliminated, and my hair looks as healthy and bright as ever — I did get a slight trim after my before photo was taken, but my color has not been touched! Friends and colleagues began asking whether I had recently gotten my hair highlighted or if I had been blowing it differently to give it even more body. My blond waves were finally getting the attention I waxed nostalgic about from my teenage days.

Up until this experiment, I didn't give much thought to investing in shampoo or conditioner. I had tried out a few expensive products over the years but never noticed a big enough difference to make the habit stick, but as long as my current budget allows for this luxury, I'll be hooked on this hair care
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