CDC Survey: 44% of U.S. GLP-1 Users Skipped Doses or Otherwise Changed How They Took the Drugs

The CDC has put a national number on how many Americans don't take GLP-1 drugs as prescribed. The answer: 44% of users.

The figure comes from a report in the CDC's Morbidity and Mortality Weekly Report, published Nov. 12 (volume 75, issue 44) by Samantha Pierce, Lilanthi Balasuriya, Lyudmyla Kompaniyets and Alyson Goodman. It draws on the agency's Rapid Surveys System, which collected answers from 8,118 U.S. adults in July and August 2025.

How many people use GLP-1s

An estimated 9.8% of adults reported using a GLP-1 medication in the past year. That works out to roughly 27 million people.

Use is concentrated among people with chronic conditions. According to the report, 47.4% of adults with diabetes used one, and use climbed with body weight: 8.1% of overweight adults, versus 24.1% of those with severe obesity. Women reported higher use than men, 11.9% versus 7.6%.

What "modified use" means

Only the 976 users in the sample got follow-up questions about how they took the drugs. Of those, 44% said they had changed their use from what was prescribed.

Skipping doses topped the list at 28%. Others delayed refills or took smaller doses than prescribed.

Among people who made changes, 38% cited cost and 36% cited availability. About 12% of users said they reduced or stopped the drug because of side effects or symptoms.

Age was the sharpest divider. Modification rates were 54% among users ages 18 to 39 and 30% among users 65 and older. Delayed fills were reported by 37% of the younger group and 6% of the older group. And 58% of younger users who changed their regimen pointed to cost, compared with 20% of older users.

Compounded versions

About 22.6% of GLP-1 users said they used a compounded version, and another 8.8% did not know whether theirs was compounded. The FDA does not review compounded GLP-1 products for safety, effectiveness or quality before they are sold.

The modification rate was 62% among compounded-drug users, against 36% among everyone else.

The CDC said better understanding of real-world use, including compounded products and dose and frequency changes, matters because it "might have implications for safety and effectiveness." The agency added that more evidence on those practices could help guide clinical guidelines.

Limits of the data

The survey relies on self-reported answers. The two survey panels had cumulative response rates of 13.3% and 3.8%, which is low.

The data also predate recent moves on price and access. The Medicare GLP-1 Bridge program, which began July 1, offers eligible beneficiaries weight-loss drugs for $50 a month. Eli Lilly and Novo Nordisk have also pushed to make their products easier to get, according to Bloomberg. Without insurance or discounts, FDA-approved weight-loss drugs carry a sticker price that can top $1,000 a month, which helped drive demand for compounded versions during shortages of approved products.

The Medicare program is paid for by taxpayers. Whether it changes how seniors take the drugs is not something the 2025 survey can answer, though the CDC data already show older users were far less likely than younger ones to name cost as a barrier.

Why stopping matters

A separate study reported by CTV News found that people who stop taking GLP-1 drugs face a doubled risk of heart attack, stroke or death. Cardiologist and epidemiologist Dr. Christopher Labos told CTV News the findings reinforce that GLP-1 medications "protect your heart."

The CDC survey does not measure health outcomes, so it cannot link the 44% figure to any such risk. Skipping a dose is also not the same as quitting.

Access outside the traditional system

A separate preprint from researchers at the University of Southern California and RAND, posted to medRxiv and not yet peer-reviewed, tracked GLP-1 and GLP-1/GIP use across three survey waves in 2024 and 2025. It counts prescriptions from online providers or medical spas, fills from foreign, compounding or online pharmacies, and use with no prescription as "non-traditional" access. The authors argue that insurance records can miss some of these routes.

The survey data cover only July and August 2025, before the Medicare bridge program began. A later survey would be needed to show whether that program and the manufacturers' price moves have changed the 44% figure.