How a Keratin Treatment Changes Your Hair



In our new series, The Science of Beauty, we're going to do a bit more research into the making of a great beauty product. While we've talked about the textures, scents, and efficacy of our favorite formulas in our Reviewed series, this one is meant to feed the other side of the brain—the side we perhaps haven't tapped into since chemistry class. We'll talk science, experiments, and the ingredients that make each product work with experts in each specific field. Then we'll check back in with our favorite hair and makeup artists to get a breakdown on how to best use the products once they're out of the lab and back in our bathrooms.

We dove deep into the technology behind volumizing hair products, learned about the history and chemistry behind antiperspirant, and read up on Accutane. Now, we're talking keratin treatments. The hours-long, in-salon remedy works to de-frizz and de-puff, but how does it work? What exactly can keratin do for the hair? And is it suitable for all hair types? Needless to say, we have some lingering questions. To get some answers, we talked to the team at Keratin Complex along with pros in the hair industry, Jerome Lordet, head stylist at Pierre Michel Salon, and Annagjid "Kee" Taylor, celebrity hair stylist and author of All Hair Is Good Hair. Keep scrolling to learn everything you need to know about getting a keratin hair treatment.

What is a Keratin Treatment?

Keratin is a fibrous protein found naturally in the hair that acts as a protective shield against humidity (the primary cause of frizz). Over time, the hair loses keratin from exposure to the sun, environment, styling, and chemical services—causing porous spots to develop (much like potholes in a road). "Keratin in and of itself works with the porosity of the hair. Most frizz, damage, and tangled hair is due to overly porous hair," says Abraham Sprinkle, a Keratin Complex International creative team member. "Keratin treatments fill in the gaps where keratin has been depleted, so humidity is combated and hair is left with a healthier appearance. Think of it in the same way spackle deals with nail holes in sheetrock: The surface is left smooth."

There are a variety of keratin treatments to choose from, Brazilian blowout (where the hair texture is straightened out) being the most popular. "A keratin treatment is more for smoothing and frizz control compared to a straightening treatment, which is to actually straighten the hair," explains Lordet. "While the keratin treatment may straighten hair a little bit, it keeps more body in the hair than a straightening treatment." Sprinkle agrees, adding that "Unlike straightening treatments (which can break protein bonds to reform hair structure into a permanently straight shape), the Keratin Complex treatments specifically won't break the bonds of your hair—instead, they reduce frizz and restore health to provide the straightening, smoothing effect without permanently changing the structure. This allows versatility to style wavy or straight as desired."

Performed in-salon by a professional stylist, this powerful treatment replenishes the hair with high concentrations of keratin that penetrate throughout the hair structure and are sealed within the cortex to repair the damage. "This locks out humidity, repairs damage and breakage, and rebuilds strength to make smoother, shinier and healthier-looking hair, improving manageability and significantly reducing styling time," Sprinkle explains.

Depending on where you go to get a keratin hair treatment, it can cost anywhere from $300 to $600 per treatment. (For reference: at Pierre Michel Salon, it costs $450 for a single treatment).

Benefits of a Keratin Treatment

Keratin treatments carry a host of benefits for strands.

  • Can cut blow-drying time in half
  • Prevents frizz in humidity
  • Smooths out the hair cuticle
  • Hair doesn't tangle as easily
  • Imparts a lustrous shine

According to Taylor, a keratin hair treatment is great for those with frizzy hair, and is a healthier option to other straightening treatments (such as relaxers). "Because keratin treatments fill in the porous gaps in your hair strands, it completely smooths out your hair and will keep it free from frizz," she says. "Also, one of the key benefits of a keratin treatment is how it smooths out your curl pattern. If you're pressing out your hair regularly, this will save you a lot of time." In terms of shine-factor, those with naturally curly hair typically don't see shine in their hair (curls reflect light less than straight hair)–with a keratin treatment, your hair will appear loads shinier.

How to Prepare for a Keratin Treatment

As with all chemical processes for the hair, a keratin hair treatment should be done by a professional, and you should always discuss any required preparation with them. That said, Lordet advises to lay off coloring your locks pre-treatment, as the chemical can strip out the color and alter it. Finally, you should make sure you're not sensitive to formaldehyde, as Taylor notes that it can cause reactions such as stinging, itching burning eyes, nose and throat irritation, and a runny nose in those with sensitivities. (As a side note, keratin treatments are not recommended for women who are currently pregnant.)

If you have fine and very straight hair, Lordet advises against doing keratin treatments, as they can make the hair appear flat and bodiless.

What to Expect During a Keratin Treatment

"A technician will shampoo your hair twice with clarifying shampoo to ensure the hair is really clean, free of any buildup or residue, and ready to absorb all the product," explains Lordet. "Then, the keratin solution is applied to the wet hair and combed through. (Note: the solution may feel a little itchy on the scalp.)" The length of time for a keratin treatment depends on the formula being used, as well as your hair texture and how much hair you have—Taylor notes that it typically takes two to four hours. As the final step, the hair shape is further adjusted with the assistance of heat—first with a blow-dryer and finally with a flatiron, sealing in the treatment to create a humidity-resistant finish and smooth silky strands.

Side Effects

Though keratin treatments do not damage the hair, a flatiron at a very high temperature can. Always use a professional titanium flatiron and professional judgment when selecting the flatiron temperature—start at the lowest recommended temperature and increase only if necessary. "Keratin treatments can last up to six months, but you may find that it impacts your curl pattern permanently," says Taylor. "To maintain your results, you must use sodium chloride-free hair products. Wrap your hair in a silk or satin scarf (or pillowcase) to keep the moisture locked in your hair, as the treatment can cause your hair to dry out faster."

Lordet adds that you can help its longevity by not shampooing too often (over time, this can wash the keratin out). "I recommend using a natural dry shampoo between washes—the Cleo & Coco Dry Shampoo + Body Powder ($14) is great for adding body and keeping the hair refreshed," he says.


"After doing the treatment, avoid washing hair right away to allow for the product to sit in," says Lordet. You'll also have to avoid touching it or putting it up for three days post-treatment to avoid denting. Taylor adds, "If you don't take care of the treatment after, it will do more harm to your hair than good. Keratin treatments contribute to hair thinning and excess hair shedding if not cared for properly due to the high heat and chemicals involved."

Before and After

The Final Takeaway

Keratin is great for those who have frizzy hair and want long-term straight, smooth hair. If you are looking to bounce between your natural curls and straight hair, this may not be the solution for you.

Article Sources
Byrdie takes every opportunity to use high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial guidelines to learn more about how we keep our content accurate, reliable and trustworthy.
  1. Basit A, Asghar F, Sadaf S, Akhtar MW. Health improvement of human hair and their reshaping using recombinant keratin K31. Biotechnol Rep (Amst). 2018 Oct 24;20:e00288.

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