There was once a time when those who wanted smooth hair had to literally iron it out. Now there are tools and technologies specifically designed to straighten strands instantly. Among the most popular? Semi-permanent salon-grade treatments that leave hair smooth with zero effort on your part. 

The two biggies, of course, are keratin treatments and Brazilian blowouts. Both of these treatments are lauded for their ability to reduce frizz and can deliver jaw-dropping results. But though they may offer similar effects, they’re two entirely different treatments. Understanding how they work (and who they’re best for) is critical for choosing which one’s best for you. 

“Both treatments are great for smoothing, but the main difference is what kind of results they can give,” says Christina Giarrizzo, a celebrity hairstylist at Voel Hair in New York City. “A Brazilian blowout will eliminate frizz and even straighten curly hair, while keratin will make your hair straighter and more manageable without damaging the integrity of the hair’s structure.” 

So, which one will give you the smoothed-out strands of your dreams? Keep reading to find out how to pick your fighter in the battle of keratin vs. Brazilian blowouts.

What Is a Keratin Treatment?

“The word keratin is somewhat of a misnomer, as keratin is not the actual ingredient that smooths the hair,” says Kathy Combs, Vice President of global education at Cezanne. “Keratin is a strong protein found naturally in skin, hair, and nails that heals and protects.” Keratin treatments, then, put this protein to work. “They apply a coat of the protein to the hair to seal in the cuticles, making it shiny, silky, and smooth,” says Giarrizzo. “The result is hair that is more moisturized, manageable, and, best of all, easier to style.”

Best Candidates

According to Giarizzo, the best candidates for keratin treatments are those who have curly or frizzy hair. Additionally, this treatment can also be helpful for those who have thicker or more coarse textures and are looking to make their hair more manageable. 

That said, “The best person to determine if your hair is suitable for a keratin treatment is a licensed, professional salon stylist,” says Combs. “The first step to receiving a keratin treatment is to schedule a consultation with your stylist. During the consultation, your stylist will ask questions to help determine which treatment is best suited for your hair type and hair goals.”

Not Ideal Candidates

If you already have very thin, fragile hair, this treatment isn’t for you. It even can cause more damage than good. “Because keratin is designed to help thicker and coarse hair more manageable, it’s not ideal for people with superfine hair or those prone to breakage,” says Giarrizzo. “Especially considering the high heat of the flat iron used.”

Typical Cost

The average keratin treatment costs between $200 and $800. “The price shifts based on several factors, including the length and density of a client’s hair, the amount of time the application takes, and the formula longevity, which can span from 10 weeks to five months,” says Combs.

How Long Does it Last?

A keratin treatment lasts between four weeks and five months, depending on the formula that was used and how well you’re caring for your hair.

What Is a Brazilian Blowout?

Brazilian blowouts are a type of keratin treatment that takes things one step further to smooth and straighten strands. This treatment uses a proprietary blend of amino acids and proteins (including keratin) and is devoid of the formaldehyde that’s often found in keratin treatments. “A Brazilian blowout uses a liquid keratin formula that creates a layer over each strand of hair, and is sealed in with heat, to help straighten and smooth hair,” says Harry Josh, a celebrity hairstylist and Kerasilk ambassador. Unlike keratin treatments, which are fairly “one size fits all,” Brazilian blowouts can be customized depending on the texture you’re trying to achieve.

What to Expect

Brazilian blowout appointments typically last between two and four hours (depending on the length and thickness of your hair), and always begin with a consultation. “The client will first share their desired results with their stylist and discuss potential customization with heat styling,” says Josh. 

Then, the stylist will wash and towel dry the hair before applying the treatment from roots to end. “Because this treatment does not have any processing time, the stylist will then blow dry the hair with the applied treatment, typically using a round boar brush to style the hair,” says Josh.

Best Candidates

Anyone who wants smoother, straighter hair can benefit from this treatment. Keep in mind that Brazilian blowouts leave your hair pin-straight with little volume or texture. If you’re looking to maintain some body or volume, you may want to opt for a standard keratin treatment instead.

Not Ideal Candidates

If your hair is already silky smooth, spare your hair from the chemicals and skip this treatment. And, again, if you’re looking to decrease frizz but still want some texture, a Brazilian blowout isn’t for you.

Typical Cost

Brazilian blowouts can cost anywhere between $95 to $400. However, experts say the average price rounds out to $300.

What to Consider

When trying to choose between these two hair treatments there are two main factors to consider—hair texture and your desired result.

Hair Texture

“The biggest thing to consider here is your hair type,” says Giarrizzo. “Both treatments are semi-permanent and can help improve your hair’s texture. Keratin treatments are best for people with wavy hair and Brazilian blowouts are better for people with dry or frizzy hair. Depending on what kind of hair you have, the results will be better if you do the treatment that works best for you.”

Desired Results

Though these two treatments are similar in a lot of ways, they can leave you with totally different results. “A Brazilian blowout is designed to help defrizz hair and give it a straighter texture,” says Josh. “A keratin treatment is similar in that it defrizzes hair and cuts down on styling time, but it gives hair more of a looser body wave.”

Potential Risks

The biggest risks associated with keratin treatments come during the application process. “Some keratin treatment formulas may contain formaldehyde, a strong-smelling chemical that can cause watery eyes, coughing, wheezing, skin irritation and a burning sensation in your eyes, nose and throat,” says Combs. Even if a formula is formaldehyde-free, Giarrizzo cautions that keratin treatments tend to have a strong odor and may cause watery eyes and tingling on the scalp during treatment. 

The other thing to keep in mind is that any sort of straightening treatment—including these two—may permanently mess with your curl pattern. If that’s an issue for you, you’ll likely want to explore other options.

Aftercare

The aftercare for both keratin treatments and Brazilian blowouts is fairly simple. You’ll want to wait for three days (or more!) to wash your hair and avoid touching it at all in the first 24 hours after the appointment. 

From there, stick with sulfate- and sodium chloride-free shampoos to extend the life of the treatment. Also, remember to turn down the temperatures on your styling tools as “high heat settings should be avoided on keratin-treated hair,” says Combs. The good news is that keratin might just solve your need for hot tools—and even if it doesn’t, you’ll be able to get better results from lower heat settings than you could pre-treatment.

As time goes on, try to limit your washes as much as possible, and steer clear of chlorine. “Using products with keratin or things like silk pillowcases can also help to lengthen the results,” says Giarrizzo. 

Final Takeaways

There are plenty of different ways for you to smooth out your strands, and both of these treatments offer results that make them worth their hefty price tags. For a straighter look with a little bit of body, opt for keratin; and for stick shiny strands, go for a Brazilian blowout.