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GLP-1s are practically everywhere — roughly 1 in 8 U.S. adults take one. 

But stopping those drugs may come at a cost. 

That’s according to a new study from the Washington University School of Medicine, which was published on Wednesday in BMJ Medicine. 

The research found that even short gaps in treatment with a GLP-1 can drive up risks of heart attack, stroke and death in patients with Type 2 diabetes, and the impact may not be fully reversible. Using electronic health records, researchers followed more than 333,000 adults with diabetes over three years, and the lion’s share of them were taking Novo Nordisk‘s diabetes injection Ozempic. 

Here are the key data points:

• Patients who stayed on GLP-1s over three years saw an 18% reduction in cardiovascular risk.
• Quitting GLP-1s for as little as six months erased much of that protection, raising the risk by 4% compared with continued use.
• A two-year gap in treatment pushed that risk to 22% compared with sustained use.

GLP-1s do “much, much more than weight loss,” study author Dr. Ziyad Al-Aly, a WashU Medicine epidemiologist, said in an interview. “They’re reducing all these back problems, reducing cholesterol, reducing blood pressure, reducing insulin resistance, reducing inflammation and really offering cardiovascular protection.

“When people stop GLP-1s, that cardiovascular protection ceases to exist and what’s more is that there is some asymmetry here,” he added. “It takes years to build cardiovascular protection, and takes half as much as much to undo that.” 

Al-Aly called it a “metabolic whiplash,” where all of the improvements “go in the wrong direction” once treatment ends. 

The findings aren’t entirely a surprise. 

GLP-1s are well known for their cardiovascular benefits. In 2024, the Food and Drug Administration approved semaglutide, the active ingredient in Novo Nordisk’s Wegovy and Ozempic, for slashing the risk of major cardiovascular events in adults with established heart disease and obesity. 

But the new study offers some of the first large-scale evidence on what happens to patients’ hearts when they quit these drugs, particularly among those with diabetes. 

The research also underscores a persistent issue — high rates of quitting the drugs, driven by trouble accessing them and side effects like nausea and vomiting — that the health system has yet to fully solve. Discontinuation rates for GLP-1s run as high as 36% to 81%, according to several studies.

Al-Aly said providers and patients contemplating a GLP-1 should understand that people need to stay on treatment “for the long haul,” not for just a few months or even years. 

He also pointed to the need to address the major drivers of discontinuations, such as mitigating side effects proactively. The access issue will likely improve in the U.S., especially as major players like Eli Lilly pursue efforts to boost obesity drug coverage among employers, and as the federal Medicare program prepares to start covering weight loss treatments for the first time. 

Maintaining patients on treatment “shouldn’t be an afterthought,” he said. “People need to realize that there’s a price of stopping.”

Drugmakers are also working to solve the discontinuation issue, with hopes of developing next-generation obesity and diabetes treatments that provide comparable efficacy with fewer unwanted side effects.

Feel free to send any tips, suggestions, story ideas and data to Annika at a new email: annika.constantino@versantmedia.com.