What Is a Keratin Treatment? Two Hair Experts Break It Down (2025)

There are tons of hair treatments out there, each buzzier than the last. For instance, you may have heard of a Brazilian blowout—which gives you bouncy, luscious locks. Or you may be curious about a keratin treatment, wondering what it is, why it benefits your strands, and how it's different from a Brazilian blowout. (Basically, the blowouts will give you super-straight strands while keratin treatments will leave you with a loose wave.) If you fall into the latter, keratin-curious camp, you've come to the right place.

Two of InStyle's curly-haired editors gave keratin treatments a try and reported back with their results. Sam Reed, who has type 3A curls, tried a treatment without formaldehyde. Meanwhile, Kara Jillian Brown—who has tight, 4B-4C coils—opted for a keratin treatment with formaldehyde (more on this ingredient later). For further insight into this popular hair treatment, we also chatted with pro stylists and keratin experts Meri Kate O'Connor and Raphael Roque.

So if you're considering trying a keratin treatment, keep reading for a full breakdown.

What Is a Keratin Treatment?

A keratin treatment is a process that smooths, straightens, and strengthens your hair by providing it with keratin—which is one of the main proteins that makes up hair. "It's creating a barrier that will be temporary for a couple of months," says Roque.

Again, there are two types of keratin treatments—thosewith formaldehyde and those without it. Treatments with formaldehyde are much more effective, and the effects last longer than those without. Regardless of whether or not the treatment contains formaldehyde, though, the process will involve applying a solution with high concentrations of keratin to twice-washed hair. The keratin seeps down into hair's pores and is heat-sealed with a flat iron, leaving you with smooth, straight tresses.

Benefits of a Keratin Treatment

The process promises (mostly) straight hair with minimal maintenance, but the benefits don't stop there:

• Works on all hair types:The treatment will still eliminate the frizz/flyaways and straycowlicks. Think of it as a constant blowout without the barrel-curled ends or the complimentary champagne.
• Has restorative properties:According to O'Connor, keratin treatments can improve the texture and condition of color-treated hair to some extent. Virgin hair works best, as it's able to absorb more of the keratin. This also helps strengthen hair.
• Added texture and volume: While pin-straight hair has a time and place, sometimes you want a mane with a little more movement. Keratin treatments tend to loosen curls and coils instead of flat-out straightening them, Roque says.
• Increased strength: The keratin treatments currently on the market can help strengthen your hair by promoting a stronger follicle. "We're pumping in natural keratin and collagen into the hair again, and these properties help build a good follicle," explains Roque.
• Faster blow-dry: Although your hair will better retain moisture, water won't be holding on for dear life when you're trying to dry it. This means you won't need to apply as much heat and tension to your hair to dry it off.
• Humidity resistance: Because a keratin treatment creates a fortress around your strands, you don't have to worry about humidity ruining your look. The keratin will actually reflect humidity away from your hair to keep it straight and frizz-free.
• Formaldehyde-free options:Unlike atraditional Brazilian blowout, you can find keratin treatments that do not—repeat,do not—use formaldehyde. That said, is this completely chemical-free? No.

Who It's For

Keratin treatments really are for everybody—regardless of hair type and color treatments. Unlike Brazilian blowouts, keratin treatments offer a softer way of treating your hair. That said, since keratin treatments are meant to smooth out your hair, wavy, curly, and coily hair types may benefit from them the most.

What to Consider

The Shape You Want

There are two components to the formaldehyde-free treatment that Reed tried. The firsteliminates the frizz, and there are two options for the second component: You can either eliminate curls completely or just tame the wave/curl. Because Reed wanted a dramatic change to post on Instagram, she opted to get rid of her curls.

High-Heat Exposure

Because keratin treatments are set with heat, a lot of heat at high temperatures is needed to complete the service. When done two or three times a year, this isn't a problem—as long as you're fine with cutting back on the heat you apply at home. However, if you're tethered to your curling iron or want your hair to look picture-perfect on the daily, you're gonna suffer some heat damage.

The Keratin Treatment Process

For Reed, the treatment took a little over three hours from start to finish. For Brown, the process took closer to five hours. However, keep in mind that this will vary depending on your hair type and how much of it you have. If you have the kind ofheavy, thick manethat results in a ponytail tension headache after two hours in an updo (guilty), it will take hours.

It's best to clear your schedule and throw an extra book and your phone charger in your bag, just in case. O'Connor also notes that the process might take a bit longer with fine hair because it requires going over the sections with a flat iron a few extra times. Here's a complete breakdown of the steps:

1. Double Shampoo and Blow-Dry

The process begins with a double shampoo to completely strip away dirt, oil, grime, and products. Next, the stylist will blow-dry your hair. If you have a lot of hair, it's possible your stylist will enlist the help of an assistant to expedite the process.

2. Apply Treatment and Wait

Once the hair is 80 percent dry, your stylist will section it into three parts and begin applying the treatment itself. After painting the mixture onto your entire head, the solution will be left to sit for 15 minutes. (This was the case for Reed and Brown.)

3. Blow-Dry (Again)

Then comes the fun part. Your stylist will blow-dry your hair while the solution (which feels like aleave-in conditioner) is still in it. They typically use a wide, ventilated paddle brush. Given the thick consistency of the product, you can expect this to take quite a bit of time.

4. Flat Iron

Afterward, your stylist will use a flat iron at 450 degrees Fahrenheit to flatten curls into oblivion. Starting at the nape of the neck, they'll take sections about two to three inches wide and iron them several times. Brown notes that this process took at least three hours for her coily strands.

This process—the aforementioned thermal activation process—is the most important part of the entire service. An interesting side note, according to Reed: The flat ironing may result in big puffs of white steam. Her black cape was covered in white flakes of product, which she was assured was normal. The process was not otherwise uncomfortable (not even tingly).

5. Shampoo, Seal, and Blow-Dry

After it was dried and straightened, your stylist will do one more shampoo to wash out the solution. Finally, they'll follow up with a sealant andanotherblow-dry. Since this final blow out will be done post-treatment, it'll take much less time than any of the preceding ones. Having had curly hair since puberty, Reed and Brown admit it was shocking to watch their stylists just use their fingers while shaking the blow dryer back and forth across their scalp (rather than a round brush and a downward motion).

The Results

Once the hair was completely dry, it hung straight from the scalp with no need for touch-ups—for both Reed and Brown. The texture was smooth and silky, and you bet they spent the entire evening running my hands through it like they were in a shampoo commercial.

The Cost

Keratin treatments run anywhere from $350 to $600, depending on hair length. (Disclaimer: Our editors' services were complimentary for the purpose of this article).

Aftercare

Following the treatment, O'Connor told Reed she could even go home and wash her hair if she wanted. Four shampoos in a day felt a bit much for Reed, but she did take a dip in a pool the following weekend. Not only did her hair not curl, but after driving across the Verrazano Bridge—connecting Brooklyn and Staten Island in New York—with all of the car windows down, her hairair-driedperfectly straight. She was even able to finger-comb out the tiny tangles.

As for upkeep? Nada. Zilch. Zero. Reed and Brown continued to wash their and let it air-dry. Styling products and heat weren't necessary. Each editor could go from shower to subway to work in an hour. And in two hours, Reed's hair was completely air-dried to reveal silky-smooth tresses. Although a bit of the curl came through, it appeared as a natural wave rather than a random curly coil.

According to O'Connor, the treatment lasts about three to five months. She adds that most people who have the treatment year-round will have it done every six months.

The Bottom Line

Reed and Brown didn't have to touch a hairdryer in the weeks after their treatment. Also, they didn't have to worry about a little sweat activating any baby curls at their temples. Brown says that she'd rather not spend time attempting styles like wash-and-gos or twist-outs. So as far as a no-maintenance hairstyle is concerned, this one's hard to beat.