CDC: 27 Million US Adults Took GLP-1s in 2025, and 44% Went Off-Script

The findings landed this week in the CDC's Morbidity and Mortality Weekly Report. Researchers dug through survey responses from more than 8,000 US adults gathered in July and August 2025, then extrapolated. Their estimate: 9.8 percent of US adults, or about 27 million people, used a glucagon-like peptide-1 receptor agonist at some point in 2025.

Plenty of them didn't follow the label. Forty-four percent of users said they took their GLP-1 in a way that differed from how it was prescribed. That included skipping doses, delaying refills and dropping to smaller doses than prescribed, among other changes.

Cost and availability explain most of the improvisation. More than half of the people who altered their routine cited one of those two reasons. The pinch fell hardest on younger users: 58 percent of adults aged 14 to 39 who modified their use named cost as a barrier, versus just 20 percent of those 65 and older.

GLP-1s are already prescribed for diabetes, weight loss and a widening list of related conditions such as cardiovascular disease and obstructive sleep apnea. While the boom has been effective and wildly popular, millions of Americans have also turned to unapproved versions of the drugs. The CDC study raises fresh questions about what that real-world use means for how safe and how effective these medications actually are.