Is keratin hair straightening harmful? Hairstylist clears things up

Why keratin treatments may be harmful

Many salons claim that the procedure replenishes your hair with keratin. According to the expert, keratin is a protein that gives hair and nails their strength and elasticity.

However, the body gets keratin from food and naturally uses it to build hair. That means it's impossible to "inject" keratin into the hair simply by applying it to the surface.

"Please remember this and save your money," the expert said.

She added that the keratin advertised in shampoos, masks, and conditioners is often just a marketing tactic.

At best, these products may contain animal-derived keratin, but it has no meaningful effect on the hair.

It's also important to understand that hair cannot be reconstructed because it is a dead structure. Hair strands contain no living cells capable of regeneration, no nerve endings, and no blood vessels.

Instead, products marketed as containing keratin are applied to the hair to create a temporary cosmetic effect. According to the hairstylist, a properly selected at-home hair care routine tailored to your hair type can achieve similar results.

Formaldehyde in keratin treatments

Keratin straightening doesn't actually fill the hair with keratin as advertisements claim—it may also pose health risks.

The hairstylist explained that keratin straightening products contain formaldehyde, a known carcinogen that is released when the product is heated.

Exposure to formaldehyde fumes may cause:

• Eye irritation
• Coughing
• Dizziness
• Headaches
• Allergic reactions

Long-term exposure has been linked to chronic health conditions and an increased risk of cancer.

"Some manufacturers label their products as 'formaldehyde-free,' but that's misleading," Ruslana explained. "Without formaldehyde or formaldehyde-releasing ingredients, the straightening treatment simply wouldn't work—those chemicals are what actually alter the hair structure."