Short answer: In the label trials, modestly. In adults with overweight or obesity, systolic blood pressure fell about 4 to 7 mmHg more on Zepbound than on placebo, and about 3 to 5 mmHg more on Wegovy. Both labels also list low blood pressure as a side effect: 1.6% on Zepbound vs 0.1% on placebo, and 1.3% on Wegovy vs 0.4%, more often in people also taking blood pressure medicines.
The Wegovy (semaglutide) and Zepbound (tirzepatide) labels report blood pressure as one of several heart and metabolic measures in their weight trials. These were secondary results; the main goal of each trial was weight loss. The numbers below are the difference from placebo in the average change in systolic (top number) blood pressure.
| Trial (label name) | People | Average starting systolic | Difference from placebo |
|---|---|---|---|
| Zepbound Study 1, 72 weeks | Obesity or overweight, no diabetes | About 123 mmHg | -5.6 (5 mg), -6.7 (10 mg), -6.4 (15 mg) mmHg |
| Zepbound Study 2, 72 weeks | Obesity or overweight with type 2 diabetes | About 131 mmHg | -4.4 (10 mg), -5.9 (15 mg) mmHg |
| Wegovy Study 2, 68 weeks | Obesity or overweight with a related condition | 126 to 127 mmHg | -5.1 mmHg |
| Wegovy Study 3, 68 weeks | Type 2 diabetes with obesity or overweight | 130 mmHg | -3.4 mmHg |
| Wegovy Study 1 (heart outcomes), 104 weeks | Heart disease with overweight or obesity | 131 mmHg | -3.3 mmHg |
Most people in these trials started with blood pressure that was normal or mildly raised. The labels do not say how much of the drop comes from weight loss and how much from the medicine itself. Diastolic (bottom number) changes were smaller; for example, Wegovy in the heart outcomes trial lowered it by 0.5 mmHg more than placebo.
The Wegovy label says side effects related to low blood pressure (low blood pressure, a drop on standing, and decreased blood pressure) were reported in 1.3% of adults on Wegovy vs 0.4% on placebo, and fainting in 0.8% vs 0.2%. It says some cases were linked to stomach side effects and fluid loss, and that they were more common in people also taking blood pressure medicine. In a trial in teenagers, low blood pressure was reported in 2.3% on Wegovy vs 0% on placebo.
The Zepbound label reports low blood pressure in 1.6% of people on Zepbound vs 0.1% on placebo. It was more common in people also taking blood pressure medicine (2.2%) than in those who were not (1.2%), and it also occurred along with stomach side effects and dehydration. Dizziness was reported in 4% to 5% on Zepbound vs 2% on placebo.
Neither label gives a rule for changing blood pressure medicines when a GLP-1 medicine is started. The labels only describe the pattern: blood pressure tends to fall a little, and dizziness or low readings are more common in people already on blood pressure medicines, especially with vomiting, diarrhea or not drinking enough. Any change to a blood pressure dose is a decision for the prescriber.
Home readings help with that decision. Dose Track can log blood pressure readings alongside each weekly dose and any dizziness, so the prescriber can see how readings moved as the dose went up.
While blood pressure tends to fall, resting heart rate tends to rise slightly on these medicines. In the Wegovy heart outcomes trial, heart rate rose by an average of 3.8 beats per minute on Wegovy vs 0.7 on placebo. See heart rate on GLP-1 medicines for the label details.
Read more on Dose Track: Wegovy side effects · Zepbound side effects · Blood pressure · Placebo