Enlarge (credit: https://www.uschemlabs.com/product/semaglutide-2mg-5-vials/)

Buying counterfeit weight loss drugs from illegal online pharmacies that don't require prescriptions is, in fact, a very bad idea, according to a study published Friday in JAMA Network Open.

The counterfeit drugs are sold as equivalents to the blockbuster semaglutide drugs, Ozempic and Wegovy, which are prescription only. When researchers got their hands on three illegal versions, they found that the counterfeit drugs had low-purity semaglutide, had dosages that exceeded the labeled amount, and one had signs of bacterial contamination.

The three substandard drugs tested came from three different illegal online pharmacies, which sold them as generic semaglutide drugs for weight loss, appetite suppression, diabetes, and cardiovascular health. However, the researchers, led by scientists at the University of California, San Diego, and the University of Pécs in Hungary, had initially tried purchasing counterfeit drugs from six such sellers.

Enlarge / Packaging for Wegovy, manufactured by Novo Nordisk, is seen in this illustration photo. (credit: Getty | Jakub Porzycki)

With the debut of remarkably effective weight-loss drugs, America's high obesity rate and its uniquely astronomical prescription drug pricing appear to be set on a catastrophic collision course—one that threatens to "bankrupt our entire health care system," according to a new Senate report that modeled the economic impact of the drugs in different uptake scenarios.

If just half of the adults in the US with obesity start taking a new weight-loss drug, such as Wegovy, the collective cost would total an estimated $411 billion per year, the analysis found. That's more than the $406 billion Americans spent in 2022 on all prescription drugs combined.

While the bulk of the spending on weight-loss drugs will occur in the commercial market—which could easily lead to spikes in health insurance premiums—taxpayer-funded Medicare and Medicaid programs will also see an extraordinary financial burden. In the scenario that half of adults with obesity go on the drug, the cost to those federal programs would total $166 billion per year, rivaling the programs' total 2022 drug costs of $175 billion.