02/11/2026 | Leandro Maia | Sechat

https://sechat.com.br/noticia/anvisa-alerta-para-riscos-das-canetas-emagrecedoras-e-debate-sobre-alternativas-terapeuticas-cresce 

Anvisa warns of the risk of pancreatitis and reinforces that weight loss pens require a prescription and medical supervision.

The Brazilian Health Regulatory Agency (Anvisa) has issued a new warning about the use of drugs known as “weight loss pens.” The guidance is clear: these drugs should be used exclusively as indicated in the package insert, with a prescription and medical supervision.

According to the agency, there is a risk of serious adverse events, such as acute pancreatitis, a condition that can progress to necrosis and even lead to death. Between 2020 and last year, 145 reports of suspected adverse events related to the active ingredients in these drugs and different types of pancreatitis were recorded. Six cases resulted in death. Considering also reports collected in clinical research, the total number reaches 225 records.

Anvisa emphasizes that the reports are suspected and not yet proven. Even so, the data show progressive growth: from 28 cases in 2024 to 45 in last year's partial results.

The scenario is global. The UK Medicines Regulatory Agency reported that between 2007 and October 2025, it received nearly 1,300 reports of pancreatitis associated with similar drugs, including 19 deaths.

In addition to pancreatitis, Anvisa had already warned in 2024 that the use of these medications in combination with anesthesia or deep sedation may increase the risk of pneumonia. It was also reported that semaglutide, one of these injectables, can cause irreversible vision loss in some cases.

Since June, a resolution has been in force that determines the sale of these drugs only with a prescription.

Indiscriminate use and clinical risks
For Dr. Paula Vinha, from Personalized Integrative Medicine, the main problem is not only the substance itself, but the way it is being used.

She explains that these drugs act directly on intestinal and pancreatic hormones, interfering with appetite, gastric emptying, and metabolism mechanisms. Therefore, they require individualized clinical evaluation, regular tests, and continuous monitoring.

According to the specialist, when there is an appropriate prescription, structured medical follow-up, and use of a product with a recognized origin and certificate of analysis, the risk tends to be controlled within the expected range for any pharmacological therapy. In her view, the increase in notifications is mainly associated with indiscriminate use, without follow-up and, in some cases, with products of dubious origin.

THC-V as a modulating approach
Within integrative medicine, Paula Vinha points to THC-V, a herbal medicine derived from cannabis, as a therapeutic alternative for patients seeking metabolic control with a personalized monitoring profile.

According to the doctor, THC-V can act on mechanisms related to appetite and metabolism, with a more discreet effect when compared to injectable pens. In clinical practice, it can be used both to wean patients off these medications and as an initial strategy for patients who choose not to use them.

She points out that the approach is not standardized: doses are adjusted according to the individual's metabolic and emotional profile and response pattern. THC-V is often associated with CBD, especially to modulate anxiety and promote adherence to treatment.

The doctor emphasizes that, as with injectable pens, the use of THC-V also requires professional monitoring. “Whenever any substance is used indiscriminately, without guidance, and with products of dubious origin, there can be complications. This applies to all medicine,” she points out.
 

Safety and individualization at the center of the debate
The increase in notifications and regulatory alerts highlights a central issue: pharmacological weight loss is not risk-free and requires technical supervision.

More than just discussing efficacy, the debate now involves safety, product traceability, and responsibility in prescribing. In this context, modulating approaches, such as the use of herbal medicines within individualized protocols, are gaining ground as part of a personalized therapeutic strategy—always under medical supervision.

For doctor Paula Vinha, the orientation is objective: any strategy for weight loss needs to be conducted with clinical responsibility, individual assessment and continuous monitoring. Whether with injectable medications or with phytotherapeutics such as THC-V, the therapeutic decision must be personalized, based on technical criteria and accompanied by a qualified professional, avoiding indiscriminate use and the risks associated with self-medication.