A major study of more than 333,000 U.S. veterans suggests that stopping popular GLP-1 drugs, even for a few months, can quickly erase hard-won heart benefits. The findings raise urgent questions about how long patients should stay on these medications — and how to help them do so safely.
For millions of people using blockbuster GLP-1 drugs for diabetes and weight loss, new research delivers a sobering message: the heart benefits of these medications can fade fast once you stop taking them.
In a large study of U.S. veterans with type 2 diabetes, researchers at Washington University School of Medicine in St. Louis found that interrupting or discontinuing GLP-1 treatment — even for as little as six months — was linked to a higher risk of heart attack, stroke and death compared with staying on the drugs continuously.
The longer people were off the medications, the more their risk climbed, largely wiping out the cardiovascular protection they had gained while on treatment.
The findings, published March 18 in BMJ Medicine, come at a time when drugs like semaglutide (sold as Ozempic and Wegovy) and tirzepatide (Mounjaro and Zepbound) have surged in use. Roughly one in eight U.S. adults now takes a GLP-1 drug, drawn by their powerful effects on blood sugar and weight — and, as clinical trials have shown, their ability to lower the risk of serious heart problems.
But enthusiasm for starting these drugs has not been matched by a clear plan for what happens next, noted senior author Ziyad Al-Aly, a WashU Medicine clinical epidemiologist and chief of the Research and Development Service at the VA Saint Louis Health Care System.
“There is enormous exuberance about starting GLP-1 drugs, but not nearly enough attention to what happens when people stop,” Al-Aly said in a news release.
Many patients do stop, often within months, because of side effects, cost or drug shortages. The new study suggests that coming off GLP-1s is not just a matter of regaining some weight. It may trigger deeper changes that quietly undermine heart health.
“Many quit after a few months because of cost, side effects or shortages. When they stop, it’s not just weight that comes back; they experience a resurgence in inflammation, blood pressure, and cholesterol. Weight regain is visible; the metabolic reversal is not,” Al-Aly added.
Tracking heart risks over three years
To understand the long-term consequences of stopping GLP-1 drugs, the research team analyzed health records from 333,687 U.S. veterans with type 2 diabetes. They compared people prescribed GLP-1 medications with those prescribed sulfonylureas, an older class of diabetes drugs that includes glipizide, glimepiride and glyburide.
Participants were followed for up to three years. Among GLP-1 users, the researchers checked every six months to see who stayed on the drugs, who stopped, and who had gaps in treatment and later restarted.
Over the course of the study, about a quarter of GLP-1 users stopped the medication, and nearly as many had an interruption of at least six months before resuming.
When the team looked at major cardiovascular events — heart attack, stroke and death — a clear pattern emerged:
- People who stayed on GLP-1 drugs continuously for the full three years had the largest reduction in risk compared with those on sulfonylureas.
- Those who used GLP-1s for two to two-and-a-half years before stopping still saw some benefit, but less.
- People who took GLP-1s for less than 18 months and then stopped did not have a meaningful reduction in cardiovascular risk by the end of the study.
- Any interruption in treatment, even if patients later restarted, reduced the overall heart protection compared with continuous use.
On average, continuous GLP-1 use for three years corresponded to an 18% lower risk of major cardiovascular events compared with sulfonylureas. But GLP-1 users who had treatment interruptions and then resumed saw a smaller benefit, around a 12% risk reduction.
Even a six-month gap in treatment was linked to a 4% to 8% higher risk of heart attack, stroke or death compared with people who stayed on the drugs without interruption.
For those who stopped and did not restart, the risks rose sharply. Discontinuing GLP-1s for one year was associated with a 14% higher risk of major cardiovascular events compared with continuous use. Two years off the drugs was linked to a 22% higher risk, effectively erasing the gains built up during treatment.
The researchers describe this pattern as a kind of metabolic whiplash.
“Our data suggest this metabolic whiplash is detrimental to heart health,” Al-Aly added. “Restarting the medication helped restore some protection, but only partially, showing that discontinuation leaves a lasting scar.”
Benefits build slowly, vanish quickly
The study underscores a crucial point: GLP-1 drugs are not quick fixes. They work over time to improve blood sugar, reduce inflammation, lower blood pressure and improve cholesterol — all factors that contribute to heart disease.
According to the researchers, those benefits accumulate slowly with consistent use, but they can erode surprisingly quickly once treatment stops. In this study, as little as one year off a GLP-1 drug was enough for participants to lose cardiovascular gains that had taken years of continuous treatment to build.
The results also suggest that simply restarting the medication may not fully undo the damage from a long break, at least over a three-year window.
For patients and clinicians, that raises difficult questions. How long should people plan to stay on GLP-1 drugs? What happens if they cannot afford them, run into shortages or struggle with side effects? And how can health systems support long-term use for those who need it?
A call to treat adherence as a core goal
Al-Aly and his colleagues argue that staying on GLP-1 treatment should be seen as a central goal of care, not an afterthought.
“Clinicians should treat adherence to GLP-1 treatment as an important outcome in its own right — not an afterthought,” Al-Aly added.
He noted that the burden does not fall on patients alone.
“Health systems need plans in place to help people continue their medication indefinitely, recognizing that GLP-1s treat chronic conditions. That includes proactive management of side effects, candid conversations about the long-term nature of treatment, infrastructure to identify and support patients at risk of stopping and addressing the cost barriers that make GLP-1 therapy unsustainable for many,” added Al-Aly.
The study focused on veterans with type 2 diabetes, a group at especially high risk for heart disease. More research will be needed to see how these findings apply to other populations, including people taking GLP-1 drugs primarily for obesity without diabetes.
Still, the message is highly relevant for anyone considering or already using these medications. GLP-1 drugs can be powerful tools for protecting the heart as well as managing blood sugar and weight — but their benefits appear to depend heavily on staying the course.
For patients, that means talking with their health care providers about long-term plans before starting a GLP-1 drug: how to manage side effects, what to do if costs rise, and what alternatives exist if they cannot stay on the medication.
For health systems and policymakers, the study highlights the need to address barriers that push people off treatment, from insurance coverage and drug pricing to supply issues and support for chronic disease management.
As GLP-1 drugs reshape the landscape of diabetes and obesity care, this work suggests that the real challenge may not be starting them — but making sure that the people who need them most can safely stay on them.
Source: Washington University School of Medicine in St. Louis