Brazilian health authorities are investigating 65 suspected deaths potentially linked to the use of weight-loss medications known as “skinny pens.” The investigation, led by Anvisa (Agência Nacional de Vigilância Sanitária), spans from December 2018 to December 2025 and represents an increase from previous reports. This news underscores the potential risks associated with the growing popularity of these drugs and the importance of medical supervision.
According to Anvisa, the number of suspected deaths has risen significantly, from six investigated earlier this month to 65 currently under review. The agency has also updated the number of reported adverse events to 2,436, up from a previous count of 225. These medications have gained prominence as aids in managing diabetes and obesity, but concerns are mounting regarding their safety.
The reported deaths occurred following the use of drugs containing semaglutide – the active ingredient in Ozempic and Wegovy, both manufactured by Novo Nordisk – as well as liraglutide and tirzepatide, the latter found in Mounjaro. “Anvisa does not investigate deaths individually. What it does is analyze notifications of suspected adverse events received as part of pharmacovigilance monitoring. The value of notifications as evidence lies in the set of data that, when added together and analyzed globally, can indicate changes in the safety and efficacy profile of medications,” the agency stated.
The investigation extends to products from compounding pharmacies and unauthorized laboratories, as well as medications smuggled from other South American countries and sold illegally. This highlights the dangers of obtaining prescription drugs through unregulated channels.
Anvisa emphasized that determining a direct causal link between the medications and the deaths is a complex process, requiring extensive clinical and scientific investigation. Authorities note that pre-existing conditions and the combination of these drugs with other medications may also contribute to adverse outcomes.
On February 9, Anvisa issued an alert regarding the risk of pancreatitis associated with the use of these weight-loss pens. The agency reported 145 suspected cases of adverse events, including six deaths, between 2020 and December 7, 2025.
Eli Lilly, the manufacturer of Mounjaro (tirzepatida), stated that its drug label identifies acute pancreatitis as an uncommon adverse reaction. The company advises patients to discuss symptoms with their healthcare provider and discontinue use if pancreatitis is suspected.
Novo Nordisk, which markets Ozempic, Wegovy, and Saxenda, acknowledged the increased number of reported adverse events internationally and in Brazil, and reinforced the importance of safety guidelines. “Whereas the risk is already listed in the approved labels in Brazil, notifications have increased in the international and national scenario, which requires reinforcement of safety guidelines,” the company said in a statement.
