Reviewed by 
There are so many at-home products for frizz that promise to deliver smooth, silky hair. But nothing quite compares to the results you'd get by booking a salon appointment for a professional keratin treatment.
How exactly do these services work? "Keratin is a protein naturally found in your hair—it's essentially a building block of your hair," says Anna Chacon, MD, a board-certified dermatologist in Miami. "During these treatments, a solution containing keratin is delivered to your hair strands to smooth and help against humidity, get rid of frizzy hair, and ward off additional damage and tangles."
Meet the experts: Anna Chacon, MD is a board-certified dermatologist in Miami, Ross Kopelman, MD is a board-certified hair surgeon at Kopelman Hair Restoration, Maxwell Jarvis is a San Diego-based stylist
But the chemicals found in some of these treatments—most notably formaldehyde, which is used to open hair's outer cuticle layer so the keratin can penetrate better—have come under fire due to potential health concerns. So much so, that the U.S. Food & Drug Administration is even considering a ban on formaldehyde-based hair treatments.
So how are you supposed to get the smooth, sleek results you're after and stay safe? Here's everything you need to know before getting in the stylist's chair.
First, what is a keratin treatment?
A keratin treatment is a semi-permanent hair straightening method that aims to smooth and straighten frizzy or curly hair, says Ross Kopelman, MD, a board-certified hair surgeon at Kopelman Hair Restoration. It involves applying a keratin-based solution to the hair, which is then sealed in the hair shaft using heat, he explains. You may be most familiar with these treatments via one of the popular brand names, the Brazilian Blowout.
If you find yourself with any of the above concerns—or are even are concerned with the puffy appearance of hair or want straighter hair—a keratin treatment can work wonders, leaving the hair looking healthier, straighter and smoother. It can even help prevent hair breakage, says Dr. Chacon.
What does a keratin treatment entail?
While there are at-home keratin treatments available, the doctors and hairstylists we spoke to say they'll never quite compare, results-wise, to what you'd get in a professional stylists' chair. "Salon treatments deliver unmatched smoothing results," says Dr. Chacon.
Those appointments generally have multiple steps. First your hair will be washed with a PH-balancing shampoo, says Maxwell Jarvis, a San Diego-based stylist. "We then apply the solution in fine sections about 1/4-inch from the scalp." The solution typically sits on hair for a period of a few hours, depending on your hair length, type, and texture.
The treatment itself is then followed by a blow out and flat iron process seven times, scalp to ends, to seal in the smoothing ingredients. "We typically recommend that our client wait 48 hours before shampooing it out," says Jarvis.
How long does a keratin treatment last?
Sounds like a pretty long process, right? It sure is, but you'll also reap long-lasting results. "The keratin treatment can last up to 3 to 5 months," says Jarvis. The reason it lasts this long is to give the chemicals enough time to penetrate the hair shaft and work, says Dr. Chacon. To get the most staying power out of your keratin treatment, limit the amount of times you wash you hair each week, use sulfate-free shampoo, and try to use hot tools as less as possible.
Are keratin treatments safe?
There are some valid safety concerns regarding treatments that contain formaldehyde and other chemicals, says Dr. Chacon. One National Institute of Health study of nearly 34,000 women found that those who used hair straightening products more than four times a year were twice as likely to develop uterine cancer. Researchers didn't pinpoint which ingredients were to blame for these effects, but formaldehyde has been classified as a known carcinogen by the International Agency For Research on Cancer. People are exposed because the chemical is applied directly to the hair and sometimes even comes into contact with the scalp. When heated, it can also vaporize.
In addition to a suspected connection to some cancers, one study also found that some keratin straightening treatments can cause eczema-like rashes. "Exposure is key here and knowing how much formaldehyde is in the specific treatment is important information to have, and can vary from salon to salon," says Dr. Chacon. But it doesn't take much to experience the ill effects: Even amounts as low as 0.1 parts per million of formaldehyde in the air can cause watery eyes, nausea, coughing, and wheezing, according to the American Cancer Society.
For all of these reasons, it's best to proceed with extreme caution—and to do your homework. Dr. Chacon notes that there are now many straightening treatments that use formaldehyde alternatives, so reach out to your salon and confirm what services they offer.
And, finally, you shouldn't overdo any type of keratin treatment—both because of potential chemical exposure over time and for the sake of your hair's health. "I don’t suggest anyone with over-processed hair or very damaged hair get them done regularly, if at all, because of the excessive heat used to smooth the hair out," says Jarvis. And if you're pregnant or breastfeeding, steer clear altogether.
How much do keratin treatments cost?
Prices vary based on your geographic location and the salon you choose, but you should expect to spend upwards of $250, possibly even as much as $500.
Is a keratin treatment worth it?
While these treatments save time perfecting the at-home blowout or splurging on frequent salon styling, you'll want to weigh all the pros and cons before proceeding. On the one hand, keratin services can help minimize cumulative damage to hair, since you won't have to use heat tools as frequently as you once did. On the other, some come with pretty hefty health risks that must be considered.
Strongly consider going with treatments that do not contain formaldehyde and other harsh chemicals—even if the results aren't quite as good—and definitely limit your exposure as much as possible.
Brigitt is a writer, editor and craft stylist with nearly 15 years of experience. She specializes in lifestyle topics, including home, health, parenting, beauty, style, food, entertaining, travel and weddings. She has written for Glamour, People, Good Housekeeping, Women's Health, Real Simple, Martha Stewart, Apartment Therapy, The Spruce, and more.
Brian Underwood is the beauty director at Women’s Health. He is an award-winning journalist with more than 15 years of experience covering beauty and lifestyle for several national media outlets and previously served as beauty and wellness director at Oprah Daily. His work has appeared in Woman’s Day, Life & Style Weekly, Good Housekeeping, and many more. He also serves as a member of the Skin Cancer Foundation’s gala committee and lives in New York City with his daughter.
