According to the Academy of Medicine, the practice of Brazilian straightening, a chemical process used to straighten hair, is the cause of acute kidney failure. In question, theacidacid glyoxylic content in products.
The Academy of Medicine warns this Friday, June 7 in a press release on the risks linked to chemical straightening of hair. This practice, known as Brazilian straightening, is carried out using chemical agents. THE formaldehydeformaldehyde was first used but, classified as carcinogenic, was replaced in 2013 by glycolic acid derivatives, notably glyoxylic acid. “ In the United States, in 1998, the Cosmetic Ingredient Review considered these agents “safe” for short-term use, a concentration ≤ 30% and a final formulation pH ≥ 3, without however justifying these limits. », notes the Academy.
According to several scientific articles, these products present health risks. “ In 2023, lesions of regressive acute renal failure with the presence of oxalate crystals calciumcalcium in kidney biopsies have been described in 26 young patients, after a “Brazilian-style” hair straightening procedure, which is confirmed by a recent observation reporting the case of a 26-year-old woman, with no medical history, who presented three consecutive episodes of acute renal failure regressing after hair straightening “, we read in the press release.
In question ? The formation of oxalic acid crystals in the renal tubules, after absorption of the product by the skin and scalp. It is also specified that the product used by the 26-year-old patient contained 10% glyoxylic acid, i.e. a concentration well below the 30% product concentration not to be exceeded.
The same substance as for skin peels
The causal link has been demonstrated in mice withapplicationapplication on the skin with a smoothing product containing 10% glyoxylic acid. After 24 hours, the crystals were found in the urine of animals that had received the cream. None in control mice to which control cream was applied.
Glyoxylic acid is also used in facial peels — a chemical practice that involves removing dead skin cells — at concentrations sometimes close to 30%. “ The absorption of glycolic acid by the skin depends on the pH of the product, its concentration, the durationduration exposure to the skin and properties lipophiliclipophilic of the product. An observation of acute renal failure, in a kidney transplant patient 4 years ago, was described after 5 facial peels with glycolic acid (at a concentration between 40 and 70%)). Kidney biopsy revealed the presence of oxalate crystals “.
Alert message on Brazilian straightening
While the use of these cosmetic products is widely democratized among women and also among men, the Academy of Medicine formulates these four recommendations:
- disseminate warning and information messages to health professionals, hairdressing salons and businesses selling cosmetic products based on these acids, in order to make them aware of these risks of acute kidney failure occurring within 24 to 48 hours after the technical procedures;
- inform users about the risks in the event of frequent use of these straightening products, and about the signs of acute kidney failure, in particular acute abdominal pain, nausea, rapid onset vomiting;
- do not perform hair straightening or “peeling” in case of damage to the scalp or facial skin, which increases the penetration of glyoxylic acid and glycolic acid;
- develop cosmetovigilance to assess the frequency of risk linked to the use of products based on glyoxylic and glycolic acids, and to establish a profile of patients most at risk.
