Curl Chemistry

Ready to revolutionize your haircare routine? Our three-part guide, in partnership with the scientists and experts at Nexxus, will completely change the way you think about your curls… and the ingredients that keep them healthy, shiny, and defined. Pick up their new Curl Define collection online and in-stores now.

There’s a reason there’s an entire chart dedicated to curl types: Whether you’re a 2C or a 4B, your texture is unique to you, so treating your curls with products designed for another hair category does them a total injustice.

That’s why we partnered with Nexxus, which has always prided itself on its beyond-the-surface approach to haircare. After a decade-long research program, their renowned proteomic science experts discovered that the proteins within curly and textured hair are completely different than those in other hair types. By infusing these proteins into its brand-new Curl Define collection, it’s changing the game for people with curls and texture. Keep reading to learn all about the science behind flawless curls—and the products to use to get them for yourself.

Game-Changing Science

First things first: Let’s nerd out a little on the science behind what makes curls unique. From here, you’ll be able to use what you’ve learned to discover why caring for your texture in a new way means the difference between a so-so style and strong, moisturized, and defined curls. Just hover over the hot spots below.

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The Power of Protein

For decades, we thought a strand of curly hair simply had a different structure than a strand of straight hair. Thanks to Nexxus’s research, we now know the protein in curly hair is different too: It’s rich in the protein building blocks glycine and serine amino acids. Every product in Nexxus’s Curl Define collection is infused with silk protein, which was specifically chosen because it features high levels of these essential building blocks—and because of its luxurious softness, strength, and elasticity.

The Proof Is in the Protein

Curly girls are known for their complex hair cocktails. But while mixing up a couple of pumps of serum, a dropper-full of oil, and a scoop of smoothing cream may yield decent results, it’s also a serious time- and money-suck. (And, hello, messy!) Thankfully, Nexxus isolated the most impactful ingredients and packed them into a few extremely effective products.


Rich in glycine and serine amino acids, the key building blocks that differentiate curly hair from straight hair, this Nexxus ingredient advancement deposits the most essential proteins exactly where curly hair needs it most.


Prized for centuries for its ability to deeply nourish and protect even the most damaged strands, marula oil also happens to be super lightweight. No greasy, weighed-down hair here!


A natural, fatty acid–rich oil that lubricates the hair shaft to help decrease breakage, it also detangles better than anything else we’ve tried. Find it in Nexxus’s Ultra-8 Pre-Wash Treatment.



This skincare standby is just as effective for hair. Thanks to fatty acids, not only does it deeply moisturize, but it also effectively locks in all that hydration too. In Nexxus’s Ultra-8 Pre-Wash Treatment, it also detangles and leaves behind the healthiest shine.


See the Science

Holographic celebrities, five-foot pizzas, internet-breaking animals… sometimes you just have to see it to believe it. Try our interactive slider to see how real women used the Nexxus Curl Define collection to take their hair’s health and definition to the next level.

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