Agadir – The Moroccan Agency for Medicines and Health Products (AMMPS) has issued a public health alert about the use of certain hair‑straightening products containing the chemical glyoxylic acid, warning that their use may be linked to acute kidney damage.
In an official cautionary statement, the agency urged users, hair‑care professionals, and healthcare providers to be aware of the potential dangers associated with products that include glyoxylic acid, a substance used for its hair‑smoothing properties.
Glyoxylic acid’s effects on the kidneys
According to AMMPS, scientific evidence suggests that glyoxylic acid, if absorbed through the skin during hair‑straightening procedures, can convert into crystalline forms within the body. These crystals may then accumulate in the kidneys, where they have the potential to cause serious renal impairment, including acute kidney failure.
The agency highlighted that this risk is linked to international scientific data and has led to similar health alerts elsewhere, including in Europe. In particular, the French national health safety agency (ANSES) has previously warned that glyoxylic acid in so‑called “Brazilian straightening” treatments might be responsible for cases of kidney failure.
In its alert, AMMPS specifically advised the consumers to avoid using hair‑straightening products that contain glyoxylic acid and should seek immediate medical attention if they experience unusual symptoms during or after a treatment. Symptoms of concern include nausea, extreme fatigue, and lower back pain, all of which can be associated with kidney distress.
In addition, it urged professional hairdressers and salons to stop using products containing glyoxylic acid. The alert further encouraged healthcare professionals to watch out for unexplained cases of acute kidney failure and to ask patients about recent hair treatment product use if kidney‑related symptoms are present.
Anyone experiencing adverse effects after using cosmetic products, including hair‑straightening treatments, should report these events to AMMPS under the national cosmetic vigilance system.
Global regulatory alerts on Glyoxylic Acid in hair treatments
This Moroccan alert aligns with earlier warnings from European regulators.
In October 2024, the French health authority ANSES, together with consumer protection and health officials, issued an advisory after receiving several reports of acute kidney failure linked to hair‑straightening products containing glyoxylic acid. These reports led French authorities to advise against such products while further risk assessments were conducted.
ANSES and related agencies have noted that glyoxylic acid, often marketed as an alternative to formaldehyde in Brazilian straightening treatments, is a chemical ingredient with potential toxicity, and its use in cosmetics may need to be re‑evaluated under broader regulatory standards.


