Counterfeit Weight Loss Pens Can Cause Organ Damage – 11/28/2025 – Balance and Health

Amid the increase in the consumption of weight-loss drugs and the demand for counterfeit versions, the Federal Police carried out on Thursday (27) an operation against an underground network for the production, retail and marketing of weight-loss pens with the active ingredient tirzepatide, found in Mongaro, an injectable drug used to treat diabetes and obesity.

According to experts, the use of counterfeit medicines can cause health risks, as it is not known with certainty what substance is contained in the product. It can also cause contamination if the syringes are not sterile. Moreover, in the case of monjaro, it may not control blood glucose levels in diabetics.

In Brazil, only pharmaceutical companies licensed by Anvisa can produce and sell these GLP-1 agonist drugs. It can only be sold in pharmacies and drug stores, while keeping the prescription. It is also not possible to tamper with the drug within legal conditions, as the pharmaceutical company Eli Lilly holds the Mongaro patent.

In a statement, Eli Lilly said it does not supply tirzepatide to compounding pharmacies, medical clinics, health centers, online retailers or any other manufacturer.

“The safety, effectiveness and quality of pre-treated versions of tirzepatide by Anvisa have not been evaluated and therefore represent potentially serious risks to patients,” the laboratory says.

Fabio Moura, director of the Brazilian Society of Endocrinology and Metabolism (SBEM), says there is no guarantee that the substance in medicines sold in clinics is actually terzepatide, nor that it is in the right concentration or prepared appropriately.

The doctor says: “When producing this type of medicine, it is necessary to follow strict technology to avoid contamination. If this is not respected, that bottle can carry viruses, bacteria or fungi, and the person ends up injecting them into his body.”

Mora adds that it is not possible to predict the exact effects that counterfeit medicines can have on the body, but he notes that there is a risk of organ damage. “Practically speaking, the use of any fake medicine can damage organs, especially the liver, kidneys and heart, which are the main targets when it comes to inappropriate substances.”

Alexandre Hohl, director of Abiso (Brazilian Society for the Study of Obesity and Metabolic Syndrome), says that the effects of fake drugs can vary in severity, affect different organs, and even lead to death. He cites recent cases of poisoning and deaths due to methanol found in adulterated drinks.

“We recently tried this with fake distilled beverages, which had methanol in their composition, because they did not respect the necessary quality control processes,” he says. “Imagine pharmaceuticals. Imagine a complex peptide like terizopathide.”

There is also the possibility of not achieving the expected effect (blood sugar and weight control), or even achieving the opposite effect. “The glucose level rises again, the blood glucose level becomes out of control or there is simply no improvement even with the use of injections,” explains Mora.

The risk of syringe contamination should also not be underestimated. In a video clip posted on social media, pharmacist Laura Mares says that since the medicines are injectable, “they must be sterile, that is, they cannot contain microorganisms.” According to her, not all pharmacies or compounding clinics are qualified to manufacture injections.

Photos released in the Federal Police operation show manufacturing sites in inadequate sanitary conditions and bulk materials stored or disposed of without proper packaging.

Warning signs

Doctors offer tips to determine whether a product is counterfeit or not — in this case, the advice is to immediately seek out an endocrinologist.

  • If you feel severe pain or notice severe inflammation in the area to which the medicine was applied.
  • If you have a fever or chills.
  • If there are any symptoms that differ from the pattern of use of the medication.

In addition, specialists warn about the origin of the drug and where it is sold.

“This (Monjaro) is a patented medicine, which means the formula is an industrial secret. In theory, no one knows exactly how to make it. So, how did someone manage to copy this formula? This is already a reason for mistrust,” says Mora.

He concludes by saying: “It is not permissible for a doctor to sell medicine. This is a crime stipulated by law and a serious violation of the rules of medical ethics. If the doctor is selling medicine directly, beware of him, because he is committing a crime.”