Does Keratin Cause Cancer? Unveiling the Reality!

Hey there, hair enthusiasts! Today, we’re unraveling the million-dollar question: “Does Keratin cause cancer?”

As a devoted hair aficionado who’s tried and tested countless hair products, I’m ready to comb through the facts and cut through the rumors.

So, grab your hairbrush and let’s straighten out this curly question together!

Does Keratin Cause Cancer?

Simply put, yes, keratin treatments can potentially lead to cancer. But wait, don’t panic just yet! Let’s get into the nitty-gritty of why this is the case.

cancer cells

A Deep Dive into Keratin Treatments

Keratin, a natural protein that forms the building blocks of your hair, nails, and skin, has been a popular choice for hair restoration treatments. [1]

Scientists, through their research, have discovered ways to enhance keratin binding on damaged and bleached hair to restore its health and shine. [2]

Keratin treatments, often called Brazilian blowouts, can transform your frizzy hair into a smooth, glossy mane that seems straight out of a hair commercial.

However, the catch is that these treatments involve other chemicals, notably formaldehyde, which is known to be a carcinogen.

The National Cancer Institute identifies formaldehyde as a potential cancer-inducing agent.

Even products claiming to be formaldehyde-free have been found to exceed occupational exposure limits.

Besides the cancer scare, keratin treatments come with other side effects such as headaches, sore throats, eye and scalp irritation, vomiting, coughing, dizziness, and nausea.

And yes, in some cases, these treatments can also lead to hair loss due to exposure to harsh chemicals and high heat.

Check out this detailed video of the side effects of keratin treatments:

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Here’s a video on keratin hair straightening and the process involved in smoothing all hair types:

Linking Keratin Treatments to Cancer

Every one of us wants smooth and frizz-free hair without running any risk to our own or our hairstylists’ health. But sadly, that doesn’t exist.

Brenda Kamt, a colorist specialist at LA, says: “According to the EPA, formaldehyde is a carcinogen that could cause respiratory problems if exposure is frequent.” (4)

But what even is formaldehyde, and does keratin cause cancer? There have been several studies made on this carcinogen and its allergic reactions. (5)

Formaldehyde is a popular chemical, with over 20 million tons produced yearly. It is a byproduct of cigarette smoke, automotive exhaust, and fires.

In 2004, the National Cancer Institute conducted a study that found a considerable number of cancer patients in 25,000 formaldehyde workers.

The study found that formaldehyde exposures in the funeral industry were associated with a statistically significantly increased risk for mortality from myeloid leukemia. (6)

But what does that have to do with keratin smoothing treatment?

Formic aldehyde is used to lock the hair in its new frizz-free and straight position for a couple of months until it is washed away.

The products that don’t use formaldehyde use formalin, ethanediol, methylene glycol, or methanal which release the same carcinogenic gas.

Unsurprisingly, several salon technicians refuse to do a keratin treatment altogether.

T.Cooper, an NYC-based hairstylist, says, “Some stylists refuse to do keratin treatments because there is research that shows that continued use of formaldehyde over time can have some serious consequences.” (7)

And, if that weren’t enough, can keratin cause acne too? Absolutely. An excess of keratin can cause a blockage in hair follicles, leading to pimples. Ugghh!

Things You Should Know Before Having a Keratin Treatment

If you are still adamant about getting a keratin treatment, here are some things you should know before hitting the salon.

1. Go to a well-ventilated salon

Make sure you complete the process in a well-ventilated space with open doors, windows, or even outdoors.

hair salon

2. Don’t overdo it

Brenda Kamt says, “If you’re only getting the treatment done three times per year…the risk is very minimal.”

3. Keratin reorganization changes your hair texture

You may not like the new straightened look, especially if you have beautiful curls.

4. Be prepared for scalp irritation

You will most likely get an eye or scalp irritation during the process. It’s just the way it is.

In search of a “Keratin Treatment Without Formaldehyde“? I’ve got the scoop on safer options for you to explore!

And for all the expecting moms out there, check out “Is Keratin Safe During Pregnancy?” for the 411 on baby-safe hair care.


Are keratin treatments safe?

No. Most keratin treatments contain formaldehyde which increases the risk factor of cancer.

Does keratin cause hair loss?

Yes. The process requires high heat on the hair follicle, which can damage the building materials of hair and cause massive hair loss.

What is the safest hair treatment?

Hair botox is the safest treatment that does not contain harmful chemicals and works on frizzy hair just as effectively.

Does all keratin have formaldehyde?

Most Keratin smooth products use formaldehyde except for a few brands that use other chemicals.


In conclusion, while Keratin itself is a natural protein that’s essential for our hair health, it’s the additional chemicals in keratin treatments, like formaldehyde, that raise concerns.

Though these treatments can give you that glossy, straight-out-of-a-salon look, they come with a set of potential risks, including the big C – cancer.

But hey, don’t lose heart or hair over this. There’s a bevy of other hair treatments and routines out there that can deliver fabulous hair days, minus the health scares.

So, before you book your next salon appointment, I encourage you to weigh the pros and cons.

After all, isn’t your health worth more than a few months of frizz-free hair?

On that note, what hair care routines or treatments are you willing to try for the love of good hair days?

hair keratin treatment at the salon


  • 1. Bragulla HH, Homberger DG. Structure and functions of keratin proteins in simple, stratified, keratinized and cornified epithelia. Journal of anatomy. 2009;214(4):516-559. doi:10.1111/j.1469-7580.2009.01066.x
  • 2. Baus RA, Leichner C, Steinbring C, Bernkop-Schnürch A. Strategies for improved hair binding: Keratin fractions and the impact of cationic substructures. International Journal of Biological Macromolecules. 2020;160:201-211. doi:10.1016/j.ijbiomac.2020.05.131
  • 3. Pierce JS. Characterization of Formaldehyde Exposure Resulting from the Use of Four Professional Hair Straightening Products. Published November 2011.
  • 4. Metzger C. Should You Get a Keratin Treatment? A Definitive Answer. Marie Claire. Published September 2017.
  • 5. Swenberg JA, Moeller BC, Lu K, Rager JE, Fry R, Starr TB. Formaldehyde Carcinogenicity Research: 30 Years and Counting for Mode of Action, Epidemiology, and Cancer Risk Assessment. Toxicologic pathology. 2013;41(2):181-189. doi:10.1177/0192623312466459
  • 6. Hauptmann M, Stewart PA, Lubin JH, et al. Mortality From Lymphohematopoietic Malignancies and Brain Cancer Among Embalmers Exposed to Formaldehyde. JNCI Journal of the National Cancer Institute. 2009;101(24):1696-1708. doi:10.1093/jnci/djp416
  • 7. Everything You Need To Know About Keratin Hair Treatments. Harper’s BAZAAR. Published August 9, 2022. Accessed September 5, 2022.
About Olaf Bieschke

Olaf Bieschke is a senior year medical student from Charité University of Berlin in Germany. He has gained professional experience in various hospitals and offices in Germany, Belgium, France, Poland, Brazil and Spain. Currently working on a dr. med. title thesis in neurosurgery. Follow him on LINKEDIN AND FACEBOOK. Learn more about him HERE.

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