Facts About Curly Hair Protein & Chemistry

Curls, coils, spirals… whatever you call them, it’s no secret that curly hair has a beauty all its own. That’s why it’s so important to use products designed with your hair texture in mind—because no matter your curl pattern, your hair needs extra-special products to reach its full, free, and well-defined potential.

We reached out to Nexxus Science Insights Leader Fraser Bell, a research and development expert behind Nexxus’s new Curl Collection, to get the 411 on the science behind the most epic curls—and the ingredient technology to take you there too.

Byrdie: Tell us about Nexxus’s scientific discovery that led to the formulation of the Curl Collection.

Fraser Bell: “At Unilever, research and development is core to what we do. Our team of scientists is constantly looking for ways to understand hair types and the conditions they experience and the benefits of ingredients and technologies in new ways. That’s the case here. 

“It was well-known in the hair science community that aspects of the growth of curly and straight hair are different, and Unilever R&D was one of the first groups to probe inside the hair fiber to characterize the microstructural differences resulting from curly and straight hair. It was long assumed that all hair types were composed of the same materials and that the same structural proteins were present but simply arranged differently in curly and straight hair.

“What we’ve discovered is novel. We’ve found that curly and straight hairs don’t just have different structures but that the proteins that make up those structures are actually different. Our proteomics research, the detailed study of the many different keratin proteins that compose hair, showed that there are certain proteins that are more prevalent in curly hair than straight hair, with some appearing two to six times more frequently. Those proteins are richer in specific protein-building blocks, the amino acids Glycine and Serine.

This level of knowledge is a breakthrough for Nexxus: Now that we understand the molecular-level factors that determine hair type, we can further optimize our formulas to deliver the specific products curls need.”

Byrdie: What are the key ingredients in Nexxus’s Curl Collection, and what are their benefits for curls?

FB: “Across Nexxus, our ProteinFusion blends and formulas are crafted for each collection to deliver specific benefits. Our blend for Curl Define fortifies and nourishes curls to strengthen from within and delivers an optimal level of care and conditioning at each stage of the regimen to provide luxurious softness, strength, shine, and curl definition.

“In a Nexxus first, we’ve infused Silk Protein into the Curl Define ProteinFusion blend. It’s inherently rich in the protein-building blocks of Glycine and Serine that are found in the proteins that differentiate curly hair from straight hair. We also infused Marula Oil, an ingredient known to provide nourishment.”

Byrdie: What should curly hair types keep in mind when washing their hair?

FB: “We know that curly haired people are constantly trying different routines, regimens, and cocktails to find something that works for them. With our new line, we wanted to give them the best-possible curl foundation to fortify and restore strength from within and leave their hair feeling moisturized and manageable.

“Providing care for curls starts in the shower. When curly hair is wet, it’s at its most vulnerable and prone to fatigue and breakage—it’s at this point that hair needs the most protection. We’ve designed our Ultra-8 Pre-Wash Treatment for very curly or coiled hair as a luxuriously rich formula to make detangling noticeably easier prior to cleansing.

“Our sulfate-free shampoo is mild and gentle to hair and scalp and cleanses without stripping precious moisture. Our thick, rich conditioner provides maximum slip for easy fingering-through of curls and coils and deeply moisturizes and defines.”

Byrdie: Why should curly hair types utilize a pre-wash treatment? What should they look for in one?

FB: “As noted above, curls are most vulnerable when wet, which makes the use of a pretreatment really important. Our pre-wash treatment brings eight benefits in one use: It detangles, nourishes the hair and scalp, reduces breakage, moisturizes, aligns and defines, hydrates, softens, and elongates coils and curls. These are all benefits that people with curls crave and are combined in an incredibly rich formula. This pretreatment is really versatile, and we also recommend this product as a leave-in for more coiled curl patterns, especially 4A to 4C, as an extra boost of moisture.”

Byrdie: Why should curly hair types utilize a leave-in treatment? What should they look for in one?

FB: “We know that curly hair routines are not one-size-fits-all, which is why we provide different options to deliver the moisturization that people with curly hair need. A leave-in treatment can provide a final boost of conditioning and nourishment and lock in moisture prior to styling.

“We ensured that our leave-in conditioner formula is lightweight and doesn’t feel heavy or weigh hair down. This gives the user the freedom to tailor their use to their own hair type and needs and use more where they feel it suits their hair. This product can also be used between wash days as a curl refresher and to bring back definition.”