Why keratin is bad for your hair

Keratin—the protein that helps strengthen hair to prevent breakage, heat damage, and frizz—is vitally important for maintaining strong and healthy hair. But keratin straightening, the salon treatments that promise silky-smooth hair, have long come with major health concerns.

To get the breakdown of everything you need to know about keratin treatments, we spoke with celebrity hairstylist and NatureLab Tokyo brand ambassador Andrew Fitzsimons , Eva NYC hairstylist T. Cooper , and celebrity hairstylist Annagjid "Kee" Taylor. Keratin is a structural protein found in our hair, skin, and nails. It's also commonly found in styling products to help strengthen hair—but the term keratin treatment is actually a misnomer. How the treatments work is not through the use of keratin, though.

To make hair straighter, a solution containing a formaldehyde derivative or the much safer glyoxylic acid is worked through the hair to break the bonds and reseal them in a straighter position. The solution is then blow-dried and sealed with a flat iron, and the results can last anywhere from three to six months.

He says the treatments work well on most hair types and recommends it for anyone who wants to cut out blow-drying or straightening their hair on a regular basis, reduce frizz, or boost shine. Taylor agrees with Fitzsimmons that keratin treatments work well on most hair types.

For curly hair in particular, it will completely smooth frizz and add more shine. Another added benefit is that it will keep freshly-colored hair vibrant. She recommends talking to your stylist and colorist about about getting your color refreshed right before your keratin treatment. The treatment seals in the color, making it last longer and appear brighter.

While similar to other hair straightening treatments, keratin treatments are still distinctively different. Taylor explains that keratin treatments are a less harsh option to other straightening treatments like relaxers. Your hair texture will eventually return to its natural state. With a relaxer, that is not the case at all. Relaxers break down the molecular bonds in hair, and permanently straightens it. Keratin treatments take away frizz without taking away the wavy or curly shape of your hair, unlike straightening.

So, if you have damaged, limp, weak, and dull hair, this strengthens it, especially if you tend to style it a lot. It also improves shine. This is why it is popular. Image credits: World Wide Media. Sometimes your hair needs moisture, sometimes it needs ceramides, sometimes it needs lipids. There are three concentric layers in each hair strand- the cuticle, which is the outermost layer, the cortex, the middle layer made of keratin and other substances, and the medulla.

Hydration and nutrients need to pass through the cuticles and reach the cortex in order for hair to be in good shape. But, if the cortex is too coated with proteins, it prevents moisture from reaching there. It becomes dull, lacks shine, gets tangled easily, breaks off, and loses softness. Basically, hair loses elasticity and becomes stiff and hard if you use too much keratin.

This toughness makes it more brittle. So, when hair gets pulled, it breaks more easily instead of bouncing back in shape. Keratin treatments done in salons contain ingredients like methylene glycol, formalin, methanal, and methanediol, and these release formaldehyde when mixed with water. Formaldehyde is really bad for you, and it is known to be carcinogenic.

The hair was soaked in it, and then a flat iron helped break the hair proteins and restructure it into a permanently straight shape. This keratin treatment can damage hair very easily. Fortunately, formaldehyde-based keratin treatments are decreasing in popularity. The second type of keratin treatment applies keratin directly to the hair. Instead of breaking the protein bonds and reforming them, the treatment delivers a high dose of keratin directly to the hair alongside many chemicals designed to help it seal to the filaments.

The result is essentially the same as a chemical keratin treatment — smoother, shinier hair. While gentler on the hair, hair damage can occur with this keratin treatment.

Notably, your hair needs to be left alone for several days to strengthen after a treatment. Combing it, tying it back, or even sleeping on it wrong can result in kinks or dents to your hair. However, there are a few things to be aware of when you look around for a stylist to do one for you.

Keep in mind that:. For example, one from analyzed the formaldehyde levels in seven different commercial keratin treatments.