Nickan Research Institute Journal of Renal Endocrinology 2423-6438 11 1 2025 01 01 Renal complications of hair-straightening products; a public awareness e25168 e25168 10.34172/jre.2025.25168 EN Hamid Nasri https://orcid.org/0000-0003-1673-5741 Soha Razmjouei https://orcid.org/0000-0003-1813-5846 LETTER 10.34172/jre.2025.25168 2024 07 21 2024 09 18 Systemic absorption of glycolic acid derivatives and formaldehyde causes acute renal failure after hair-straightening products. Oxalate is an end product of glyoxylic acid, which is a metabolite of glycolic acid. The dominant finding on kidney biopsy in the reported cases was acute oxalate nephropathy, which is caused by strengthened levels of oxalate that progress calcium oxalate precipitation in various tissues, comprising the renal tissue, developing toxic damage to the renal tubules and interstitium.