Keratin hair treatments may lead to kidney damage, reveals study

The popular keratin hair treatment lead to kidney problems in a 26-year-old woman, as per a study. Know its side effects!
A woman getting hair treated at a salon
Keratin treatment can lead to a number of side effects such as hair loss as well as kidney damage and respiratory problems. Image courtesy: Freepik
Anjuri Nayar Singh Published: 8 Apr 2024, 04:36 pm IST
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Keratin hair treatments have become the go-to salon solution for anyone who desires poker-straight hair. But a recent case study has highlighted the disturbing experience of a woman who ended up with acute kidney injury due to ingredients present in the hair straightening products. Besides an irritated and itchy scalp, as well as allergies and rashes, severe side effects of keratin hair treatment also include respiratory issues and liver problems.

According to the case study published in The New England Journal of Medicine (NEJM), certain ingredients used in such procedures could damage our bodily functions. The 26-year-old woman had undergone the procedure at a salon thrice between 2020 to 2022. Every visit was followed by fever, nausea, diarrhea and back pain. Doctors are said to have found high creatinine levels in her blood, signaling that her kidneys weren’t functioning normally. The report also stated that the woman did not have any kidney ailment issues previously, raising the question, “Are keratin hair treatments safe for kidneys?”

What is Keratin?

Keratin is a protein that can be found in our hair, skin, and nails. These parts are like bricks that make them strong. “To have straightened hair, people often use keratin treatments so that they can get a smooth and sleek appearance of the hair. It looks like it adds an extra layer of protection and makes the hair more controllable thereby decreasing frizz as well,” explains dermatologist Dr Priyanka Kuri.

A woman getting her hair combed at the salon
Keratin leads to smoother and straighter hair. Image courtesy: Freepik

The structure of each individual hair strand will appear smoother and straighter after being reinforced by the penetration of keratin into their shafts. This study, published in Internal Journal of Cosmetic Science, observed that keratin treatment improved the quality of hair strands by 40 percent. It smoothened them as well as increased their strength.

Can Keratin treatment lead to kidney damage?

According to experts, the reason behind the woman’s kidney damage linked to keratin treatments could be the presence of certain chemicals like formaldehyde or its releasers, such as glyoxyloyl carbocysteine. “These chemicals, while used in ‘formaldehyde-free’ hair-smoothing products, can still release formaldehyde when exposed to heat. Formaldehyde and its by-products like glyoxylate have potential nephrotoxic effects, meaning they can harm the kidneys,” says internal medicine doctor Dr Basavaraj S Kumbar.

Prolonged exposure to extreme heat during these treatments can also damage the hair, leading to structural protein destruction and weakening of the hair shaft. Besides this, experts have pointed out in the study that the presence of glyoxylic acid in such products may lead to a kidney ailment known as oxalate nephropathy.

What is oxalate nephropathy?

Oxalate nephropathy is a condition where calcium oxalate crystals build up in the kidneys, causing damage and making them not work as well, states this study, published in Clinical Kidney Journal. “This can happen for different reasons, like eating foods that are high in oxalates or taking certain medications,” says Dr Kuri. In this condition, the kidneys get clogged up with these crystals, which can lead to pain in the side, problems with passing urine, and sometimes blood in the urine.

Other keratin side effects that you must know

Hair straightening treatments—especially those involving chemical relaxers or keratin treatments—have a number of potential side effects:

1. Scalp irritation

Chemical relaxers, as well as certain types of keratin treatment can cause irritation: this leads to the scalp being red, itchy, and uncomfortable. This study, published by National Institute of Health, states that the use of chemical hair straighteners can lead to eczema, desquamation, pain, burns, and inflammation in your scalp.

2. Hair damage

Chemical relaxers also include heat-based straightening methods that weaken hair shafts resulting in breakage and leaves them dry with split ends if wrongly applied or done too often. The above mentioned study, also claims that getting such treatments done can often result in hair loss, hair damage and alternation in colour as well.

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3. Allergic reactions

Keratin side effects include allergic reactions to such as chemical compounds used in making these substances by some individuals are accompanied by symptoms like a rash, swellings or even hives.

4. Respiratory issues

Formaldehyde, a common ingredient in some hair straightening treatments, can release vapours that irritate the respiratory tract. In fact, this study, published in Toxicology and Industrial Health, states that the Formaldehyde can also lead to development of asthma symptoms or cause breathing difficulties.

5. Eye and skin irritation:

Direct contact with certain chemicals used in hair straightening treatments, such as formaldehyde or lye, can cause irritation and burns to the eyes and skin if not handled properly. The International Journal of Trichology has a published study that states keratin treatments can lead to eczema-like psoriasiform skin reactions.

6. Health risks

In extreme cases, prolonged exposure to certain chemicals used in hair straightening treatments may pose long-term health risks, including potential damage to the liver, kidneys, or sometimes respiratory system.

A woman's facing hair loss.
Keratin treatments can lead to hair damage as well as hair loss. Image courtesy: Freepik

Things to keep in mind before keratin treatment

When getting these treatments done, it is crucial to keep the following tips in mind:

  • Read the label: Check the ingredients of the product being used. Avoid treatments containing formaldehyde, methylene glycol, or similar compounds.
  • Ensure proper ventilation: Opt for treatments in well-ventilated areas to minimize inhaling harmful fumes.
  • Control temperature and humidity: Try to do treatments in places that aren’t too hot or humid to minimize heat-related damage to the hair and potential release of harmful chemicals.
  • Stay hydrated: Drink plenty of water before and after treatments to help flush out any toxins that might be absorbed during the process.
  • Avoid concurrent use of other toxic products: Minimise exposure to additional toxins that could worsen the effects of the treatment on both hair and health.
  • Prioritise health over beauty: Remember that your health should always come first. Don’t sacrifice your well-being for the sake of cosmetic enhancements.


How often should you get keratin treatment done?

This depends on your hair. But as a rule, keratin treatments should not be done more than three times a year if you want to avoid keratin side effects. If you go over and above this number, expect to face hair damage.

Who should not get keratin treatment done?

If you are pregnant, stay away from such hair straightening procedures. Other than this, if you are sensitive to allergies, then keratin might not be right for you. Also, people suffering from asthma or other respiratory problems should refrain from such treatments.

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About the Author

Anjuri Nayar Singh has over 12 years of experience in writing for various topics including lifestyle, films, television and OTT. She also writes on art and culture, education and human interest stories. ...Read More

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