Millions of Americans are not taking their GLP-1 drugs as prescribed

These versions of GLP-1 drugs are made by compounding pharmacies and are intended to mimic a medication approved by the Food and Drug Administration, such as Wegovy or Ozempic. But compounded drugs themselves are not approved by the FDA; the regulatory agency does not review their safety, effectiveness, or quality before they’re sold. While compounded drugs are considered more accessible and affordable, they generally have higher rates of preparation errors, contamination, and other manufacturing problems compared to non-compounded drugs.

Among people who used these unapproved, potentially riskier GLP-1s, 62 percent were not taking them as prescribed. That’s compared to just 36 percent of GLP-1 users who took brand-name drugs.

The potential risks of taking unapproved GLP-1 drugs at all or taking them in unapproved ways may be missed by users, the CDC researchers note. A 2025 study assessing websites selling compounded GLP-1 medications found that nearly 40 percent of sites stated or implied the drugs were FDA-approved, making it harder for consumers to differentiate the compounded versions from FDA-approved ones. Further, nearly 80 percent of sites used brand names in their advertising, which could further mislead consumers. The researchers noted that using brand names violated FDA regulatory standards.

“Given the substantial use of compounded GLP-1 medications, understanding the safety and quality of compounded GLP-1 medications is an important public health consideration,” the authors conclude. They also call for more research on the common modifications people are using, such as dose and frequency adjustments, saying the data on the safety and effectiveness of these real-world practices “could help guide the development and implementation of clinical guidelines and support appropriate medication use.”