Hypotension emerges as a risk with GLP-1 use

Clinical takeaway: Check blood pressure and ask about lightheadedness when starting a GLP-1 in patients already on several BP drugs, and consider tapering antihypertensives as weight and BP fall, especially in older or diabetic patients.

As GLP-1 prescribing targets patients with established cardiovascular and metabolic disease, many are already on one or more blood pressure treatments. New data suggest adding a GLP-1 into that mix may push some of them into hypotension.

Hypotensive events climbed to 10.2% from 8.7% in study participants within six months of GLP-1 initiation and to 14.3% from 13.6% at 12 months, both significant. The combined endpoint assessed dizziness, fainting, falls, low-BP diagnoses, systolic readings below 90 mm Hg, and prescriptions for drugs that raise blood pressure.

Older and diabetic patients carried a disproportionate share of hypotensive events. Those 65 and older accounted for 53% of them, despite representing only 37% of the cohort; patients with type 2 diabetes made up 75% of affected patients but 63% of the group. The increase persisted after accounting for weight loss, pointing to mechanisms beyond weight reduction alone.

The retrospective analysis drew on a large electronic health record database, comparing rates before and after GLP-1 initiation among 42,262 adults on at least two classes of blood pressure medication who started semaglutide, tirzepatide, or liraglutide. Events were tracked at six, 12, and 24 months. By 24 months the increase was no longer significant. The data is from a poster presented at the Endocrine Society annual meeting and has not been peer-reviewed.

The signal is small in absolute terms but clinically consequential, since a fainting episode can mean a fall, a fracture, or a car crash. It also lands at a moment when many patients obtain GLP-1s through online prescribers who never check blood pressure, leaving the earliest and highest-risk window unmonitored.

"I use a lot of GLP-1s because they are shown to reduce the risk of dying from heart disease by up to 20% depending on the population. And I noticed a series of patients on GLP-1s complaining of lightheadedness, dizziness and fainting. They had low blood pressure on my examination. Hypotension is the most dreaded potential side effect of treating hypertension and actually far more dangerous. And I started thinking that there was a pattern there that needed to be investigated," said Micah Eimer, MD, a cardiologist and clinical assistant professor of medicine at the Northwestern University Feinberg School of Medicine.

Source: Locascio T. ENDO 2026. 2026 Jun 13. GLP1 Receptor Agonists and the Risk of Significant Hypotension Among Patients with Metabolic Cardiovascular Renal Disease: Too Much of A Good Thing?