Multiple case reports and series show that keratin hair straightening with glyoxylic acid causes instant kidney damage, creating a new dangerous public health threat. The research data demonstrates that young adult women represent the primary group affected by this condition, which develops after they receive hair-straightening treatments with glyoxylic acid products at salons. The first signs of the illness appear between several hours and three days after exposure, when patients experience nausea, vomiting, abdominal discomfort and general malaise.Laboratory results in such cases show elevated creatinine and urea levels, along with hyperkalemia and acidosis. Kidney examination revealed three main findings: oxalate crystals, acute tubular injury and occasional interstitial nephritis. The majority of patients recover through supportive treatment; dialysis becomes necessary for only a few cases.
The medical condition acute kidney injury (AKI) has been found to occur in users of “formaldehyde-free” keratin hair-straightening products containing glyoxylic acid, according to recent studies. The condition affects young women who have no other health issues. This new problem creates safety issues that endanger both salon personnel and all people who undergo these treatments.What is acute kidney injuryAcute kidney injury occurs when the kidneys experience a rapid decline in function lasting from hours to days. In this condition, the blood contains dangerous substances, including waste products and electrolytes such as potassium, until they reach fatal levels requiring immediate medical care.
The main indicators of this condition include decreased urine production and darkened urine, along with nausea, vomiting, decreased food intake and fatigue. The body experiences three severe symptoms: swelling in the legs or face, shortness of breath and chest discomfort. Blood tests show that creatinine and urea levels rise quickly, potassium levels increase and metabolic acidosis occurs because blood acid levels keep rising.The case: AKI after keratin straighteningA 25-year-old female patient developed acute kidney injury (AKI) following her salon keratin hair straightening treatment with a glyoxylic acid-containing “formaldehyde-free” product. She was previously healthy and had no known kidney disease or major risk factors.She started experiencing nausea, vomiting and malaise after receiving the hair treatment. The blood tests showed creatinine levels at 3.2 mg/dL, and blood urea nitrogen at 45 mg/dL which confirmed that the patient had developed acute kidney injury (AKI). The patient showed elevated potassium levels at 6.2 mmol/L while developing metabolic acidosis, which blood tests proved with a pH of 7.25 and bicarbonate levels at 18 mmol/L. Liver tests were normal, and other common causes of AKI (dehydration, infection, drugs, autoimmune disease, obstruction) were excluded. The patient received immediate hospital treatment, including fluid administration and medical management for her elevated potassium levels and acidosis, which led to better kidney function and complete recovery. The product use triggered immediate symptoms, ruling out all other possible causes and thus proving the glyoxylic‑acid hair‑straightening product triggered a toxic reaction.
The substance glyoxylic acid creates damage to kidney tissueThe heat activation system in formaldehyde-free hair straighteners uses glyoxylic acid and its chemical derivatives to break hair bonds and create new ones. These products are marketed as safer alternatives, but their systemic effects have not been well studied.The hair straightening process allows glyoxylic acid to penetrate the scalp and skin tissues when heat is used during extended periods of contact. The body transforms glyoxylic acid into oxalate after its entry, which then forms a strong bond with calcium ions. The body creates too much oxalate, which turns into calcium oxalate crystals that build up in kidney tubules to form “oxalate nephropathy.” Research using animals shows that small amounts of glyoxylic acid entering the bloodstream produce oxalate levels that surpass the normal waste removal capacity of human kidneys. Medical reports of human kidney biopsies show that patients develop oxalate crystal deposits, along with acute tubular injury and occasional interstitial nephritis which is kidney tissue inflammation.Not an isolated caseThe case above is not isolated. Medical staff have documented multiple patients who developed acute kidney injury (AKI) following their use of glyoxylic-acid or “formaldehyde-free” hair-straightening products since 2019. Multiple countries have documented individual cases of young women who developed nausea, vomiting, abdominal pain and acute kidney injury following their hair straightening treatments at salons. The medical team performed kidney biopsies on specific patients who developed oxalate nephropathy, proving that oxalates directly damaged their kidneys. The Israeli toxicology center conducted a case series studying 13 women who used glyoxylic‑acid hair‑straightening products before their kidneys failed, and some patients showed calcium oxalate crystals in their urine.The case series shows that all patients received intravenous fluids, and most received vitamins, including thiamine and pyridoxine to possibly direct glyoxylate metabolism toward non-oxalate production.Why “formaldehyde‑free” does not mean risk‑freePeople who get keratin treatments select formaldehyde-free options because they think these products provide better protection for their hair, scalp and lung health. The products use alternative substances like glyoxylic acid instead of formaldehyde but these substances produce toxic compounds when exposed to heat. The labels do not include all products that form during blow‑drying and ironing processes and tests for systemic toxicity have not been fully conducted. European regulatory agencies have distributed warnings through their cosmetovigilance system to alert people about the potential for glyoxylic-acid hair straighteners to cause acute kidney injury (AKI). The term “formaldehyde-free” functions as a marketing label, which does not provide any assurance about organ protection including the kidneys.Practical advice for clients and hair professionalsHairdressers and salons must check product safety information to confirm their “formaldehyde-free” products lack glyoxylic acid and all its associated compounds.Users should avoid touching their scalp while following all application duration instructions and maintaining proper air circulation when using heat styling tools.Clients need to inform healthcare providers about developing new systemic symptoms following treatment while keeping records of all prescribed medications for future assessment of drug reactions.Health professionals need to evaluate hair straightening procedures as a potential reason for AKI when they see a healthy young woman who develops sudden kidney failure, along with gastrointestinal problems and urine or biopsy evidence of oxalate crystals.The bigger picture: need for regulation and researchThe collection of case reports alongside rising case series research demonstrates that glyoxylic‑acid hair‑straightening products cause instant oxalate kidney damage to individuals who possess specific medical conditions. The products stay available in stores because customers view them as safe options compared to other available products.The scientific community demands better oversight and product safety assessments for cosmetics which people can absorb through their skin and which should stay away from their scalp area. The organization demands better product labeling which should include active ingredient information and potential body-wide health effects to enable both customers and medical staff to select products wisely. Research needs to continue identifying which population members face the highest risk and to establish whether thiamine and pyridoxine medications prevent kidney damage. Disclaimer: This article is informational only and not a substitute for medical advice
