GLP-1 medications are everywhere these days. The peptide-based drugs are both highly effective and wildly popular for diabetes, weight loss and a growing range of connected chronic health conditions, including cardiovascular disease and obstructive sleep apnea. But, amid the boom, the latest data suggests millions of Americans have turned to unapproved versions and are using the potent drugs in ways doctors never intended, raising questions about what that real-world use means for safety and efficacy.

In a study published this week, researchers at the Centers for Disease Control and Prevention broke down survey data of GLP-1 use collected between July and August of 2025. Based on responses from over 8,000 US adults, the researchers estimate that about one in 10 US adults (9.8 percent) used a glucagon-like peptide-1 receptor agonist, aka GLP-1 medication, in 2025. That’s around 27 million adults. The study was published in the CDC’s Morbidity and Mortality Weekly Report.

Among GLP-1 users, nearly half (44 percent) reported using their GLP-1 in a way that was different from how it was prescribed. Users skipped doses, delayed getting refills, and used smaller doses than prescribed, among other changes. More than half of the people modifying how they used the drug said the changes were because of cost or availability reasons. Cost and access barriers were most pronounced among younger GLP-1 users. Fifty-eight percent of adults 14­–39 years old who modified their use cited cost as a barrier, compared with just 20 percent of adults 65 or older who said the same.

Modified use of GLP-1 medications was particularly common among those using compounded versions of GLP-1 medications. Among all GLP-1 users, at least 23 percent used a compounded version; an additional 9 percent said they didn’t know whether their GLP-1 was compounded or not.

Potential risks

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.”