Consumers are being urged to avoid hair products containing the chemical glyoxylic acid following the hospitalization of a 17-year-old girl who developed severe kidney failure after a hair-straightening treatment at Shaare Zedek Medical Center in Jerusalem. This marks the second such case in Israel in just over a month.
Prof. Linda Shavit, director of the Adult Nephrology Institute at Shaare Zedek, told The Times of Israel that since 2023, at least 38 women and girls have suffered acute kidney failure after using hair-straightening products containing glyoxylic acid. All required hospitalization, with several patients needing dialysis.
“There’s still danger going from curly hair to straight,” Prof. Shavit said. “It is a chemical process.”
The teenage patient was admitted in late December after experiencing vomiting, dizziness, and severe headaches following her treatment. She spent several days in the hospital before being discharged on December 29. She reportedly told doctors she would not undergo the treatment again due to the lengthy recovery.
Health Ministry Ban and Global Warnings
Products containing glyoxylic acid were banned in Israel in 2023 after a pioneering study by Prof. Shavit and Dr. Alon Benaya documented 26 cases of women and girls, aged 14 to 58, developing severe kidney failure with no prior medical conditions. The research, published in the American Journal of Kidney Diseases, was the first in the world to link hair straightening treatments to kidney failure.
Since the study, health authorities in France and other countries have issued warnings against glyoxylic acid products. However, in many regions, restrictions rather than outright bans allow the products to be purchased online and shipped internationally. “I’m sure there are still hair products with glyoxylic acid in Israel,” Prof. Shavit said.
How Glyoxylic Acid Affects the Kidneys
Dr. Marwan Abu Sneineh, a nephrology specialist at Rabin Medical Center who collaborated on Shavit’s research, explained that glyoxylic acid is safe in low concentrations used in some skincare products but can be dangerous when absorbed through the scalp during hair straightening treatments.
The chemical works by temporarily altering keratin bonds to straighten hair. Heat from hair irons can increase absorption, allowing the chemical to enter the bloodstream and convert into oxalate, a compound that can form crystals that block and damage kidney tubules.
Patients in Shavit’s study commonly experienced scalp irritation, nausea, vomiting, abdominal pain, and rash. Most were young adults with no underlying health conditions. While all recovered after hospitalization, some required intensive care, and there is concern about potential chronic kidney damage.
Safety Measures and Warnings
Prof. Shavit emphasized that straightening products should be applied at least 1.5 centimeters (0.6 inches) away from the scalp. Warning signs of chemical absorption include sudden nausea, vomiting, or changes in urination, which typically appear within hours. Immediate medical attention is critical.
Miro Vaknin, a hair stylist in Nahariya, said he only uses Health Ministry-approved products and warns customers against purchasing hair treatments from unreliable online sources. “I don’t use cheap products. People who buy from the internet or shady vendors take a risk,” he said.
Dr. Sneineh added, reflecting on a Russian saying he learned in medical school: “You need to sacrifice to be beautiful—but I don’t think anyone should have to sacrifice their health.”
