CHICAGO — Northwestern Medicine scientists have identified a safety concern associated with GLP-1 drugs. Using health record data, the research team tracked more than 42,000 adults already taking at least two types of blood pressure medications. After starting GLP-1s, these patients experienced higher rates of dizziness, fainting and other events related to low blood pressure, also known as hypotension.
These hypotensive episodes were most common among patients aged 65 and older and those with diabetes, the scientists found.
The peer-reviewed findings will be presented on Saturday (June 13) at ENDO 2026 , the Endocrine Society's annual meeting.
The study authors stress that the widely used drugs remain highly beneficial for many patients. "I'm a big proponent of GLP-1s, they are huge," said study senior author Dr. Micah Eimer, clinical assistant professor of medicine in the division of cardiology at Northwestern University Feinberg School of Medicine and a Northwestern Medicine cardiologist.
"I'm just saying, let's watch out for hypotensive events in select patients because I think there's the potential to do harm," added Eimer, who launched this study after noticing many patients on GLP-1s complaining of dizziness and fainting. "I am particularly worried about the risk to patients who obtain GLP-1s without direct and ongoing clinical supervision."
Eimer's team analyzed the health records of more than 42,000 adults taking at least two classes of antihypertensive medications who initiated semaglutide, tirzepatide or liraglutide. The scientists tracked hypotensive events over six, 12 and 24 months after patients started GLP-1 therapy and compared them with rates before GLP-1 initiation. Hypotensive events included dizziness, fainting, falls, low blood pressure diagnoses, systolic blood pressure readings below 90 mm Hg and prescriptions for medications used to treat hypotension.
