French agency warns of kidney risks in Brazilian hair straightening products, also used in Morocco

The French Agency for Health Security for Food, Environment, and Labor has issued a warning about the presence of glyoxylic acid in Brazilian hair straightening products, which can cause kidney failure. This product is also used in Moroccan beauty salons, raising concerns about the extent of control and awareness regarding its risks.

Since 2024, France has recorded four cases of kidney damage linked to these products. The General Directorate of Health and the anti-fraud agency have advised against their use. «Beware of Brazilian hair straightening products», the agency stated. A French scientific study found that glyoxylic acid, present in these hair products, can lead to kidney damage.

According to Dr. Juliette Bloch, the agency's director of warnings, glyoxylic acid can enter the bloodstream and form crystals in the kidneys, disrupting their function. Drinking plenty of water can help dissolve and expel these crystals, restoring normal kidney function.

While most cases do not have complications, it's essential to consult a doctor immediately if you experience fatigue after these hair treatments. If you notice symptoms such as nausea, abdominal or lower back pain within hours of using the Brazilian product, seek medical attention and inform your doctor, or contact a poison control center.

The agency has issued a Europe-wide warning, as the European Union has the authority to ban glyoxylic acid in cosmetic products. This substance can also be found in some hair masks or color-preserving shampoos.