For most people, yes, and by a modest amount. In the large weight-loss trials, semaglutide and tirzepatide brought systolic blood pressure down by roughly 5 to 10 points more than placebo did. When you ask where that drop came from, the answer turns out to be mostly the weight people lost.
The reason the pressure falls also explains what happens to your blood pressure medication, why some people feel lightheaded a few months in, and what these drugs can do for your heart.
The Quick Answer
Research suggests GLP-1 medications may lower systolic blood pressure by about 5 mmHg on average, with some tirzepatide data showing 7 to 11 mmHg. In a pooled analysis of 3,136 people on semaglutide 2.4 mg, the placebo-adjusted drop was 4.95 mmHg, and most of it disappeared once researchers accounted for weight loss.2 In a 24-hour monitoring study of tirzepatide, weight change explained about 70% of the effect.3 GLP-1s are not FDA-approved to treat high blood pressure, and nobody should change a blood pressure medication without their prescriber.
What the Trials Found
None of the big trials set out to study blood pressure. They were weight-loss trials. But they measured blood pressure all the same, and every large one has pointed in the same direction.
In STEP 1, 1,961 adults with overweight or obesity and no diabetes took weekly semaglutide 2.4 mg or placebo for 68 weeks. Systolic pressure fell 6.16 mmHg on semaglutide and 1.06 mmHg on placebo, a difference of about 5 points.1 The average starting blood pressure was 126/80, which is close to normal.1 These were not, for the most part, people in any danger from their blood pressure.
A reasonable person might object that this is the wrong group to study. Surely the drug would do more for someone whose pressure was actually high? Researchers asked exactly that question. They pooled the individual records from three STEP trials, 3,136 people in all, and sorted them by whether they had hypertension. It made little difference. The overall placebo-adjusted drop was 4.95 mmHg, and it stayed in the same neighborhood for people with a hypertension diagnosis (4.78 mmHg) and for those starting above 130 systolic (4.93 mmHg).2
Tirzepatide was measured more carefully. In a planned SURMOUNT-1 substudy, 600 participants wore a 24-hour ambulatory blood pressure monitor, a cuff that takes readings all day and through the night. A single reading in a clinic chair tells you about as much about a person's blood pressure as one photograph tells you about their temper. After 36 weeks, 24-hour systolic pressure was lower than placebo by 7.4 mmHg at 5 mg, 10.6 mmHg at 10 mg, and 8.0 mmHg at 15 mg, and the drop held both day and night.3
| Study | Medication | Participants | How BP was measured | Systolic drop vs placebo |
|---|---|---|---|---|
| STEP 11 | Semaglutide 2.4 mg | 1,961 | Office readings, 68 weeks | 5.1 mmHg |
| Kennedy pooled analysis (STEP 1, 3, 4)2 | Semaglutide 2.4 mg | 3,136 | Office readings, 68 weeks | 4.95 mmHg |
| SURMOUNT-1 ABPM substudy3 | Tirzepatide 5, 10, 15 mg | 600 | 24-hour monitor, 36 weeks | 7.4 to 10.6 mmHg |
It is tempting to read down the last column and conclude that tirzepatide wins. You cannot do that honestly. The trials used different measuring methods and ran for different lengths of time, and comparing them is rather like comparing two runners who ran on different tracks with different stopwatches. The table tells you what each study found and nothing more. If you want the proper comparison between the two medications, we cover it in our tirzepatide vs semaglutide guide.
How Much of It Is the Weight Loss?
Most of it, so far as anyone can tell.
Think of the heart as a pump and the blood vessels as the pipes it pushes through. A larger body is, roughly speaking, a larger house to supply, and the pump works harder to do it. Take away a good deal of the house and you would expect the pressure in the pipes to ease. The picture is simplified, of course, but the numbers bear it out. A 2003 meta-analysis of 25 randomized trials found that people who lost weight through diet and exercise lowered their systolic pressure by about 1 mmHg for every kilogram they lost.4 So when a medication helps someone lose 15% of their body weight, we should expect blood pressure to follow even if the drug did nothing else at all.
The trials suggest this is very nearly the whole story. In the pooled semaglutide analysis, once researchers accounted for each person's weight change, the difference between semaglutide and placebo shrank to about 1 mmHg and was no longer statistically significant.2 In the tirzepatide monitoring study, weight change accounted for roughly 70% of the drop.3 That leaves a little room for the drug to act on the blood vessels directly, or on how the kidneys handle salt, and researchers are still looking into it. But the weight is doing most of the work.
If your blood pressure comes down on a GLP-1, it is probably coming down because the scale is. If the weight returns, you should expect the pressure to drift up with it. We walk through what happens after stopping in what happens when you stop a GLP-1.
Why a 5-Point Drop Is Worth Caring About
You may feel that 5 points is hardly worth writing about. Anyone who owns a home cuff knows the reading can wander by more than that between Tuesday and Thursday, or between the first reading and the second. For a single reading, you would be right. Across hundreds of thousands of people, it shows up in the rate of heart attacks and strokes.
A Lancet analysis of 48 blood pressure medication trials and 344,716 participants found that every 5 mmHg reduction in systolic pressure lowered the risk of major cardiovascular events by about 10%. That held for people with and without prior heart disease, and even for people whose blood pressure was already in the normal range.5
We must be careful here, because that finding comes from blood pressure drugs, and there is no rule that lets you carry the 10% across to a GLP-1. What it does explain is why cardiologists sit up when a weight-loss medication moves blood pressure at all. Blood pressure is one of several things that shifted in the cardiovascular outcome trials we covered in GLP-1s and heart health.
And it is a common problem. About 47.7% of American adults have hypertension, and only about one in five of those have it controlled below 130/80.6 For many people starting a weight loss program, it is one of the numbers they would most like to see move.
What Happens to Your Blood Pressure Medication
Here the average of 5 points very likely undersells what happened.
In the pooled semaglutide data, among people with hypertension, 10.9% on semaglutide had their blood pressure medication reduced during the trial, compared with 5.2% on placebo. Increases went the other way: 5.7% on semaglutide needed more medication, against 7.6% on placebo.2 In people with resistant hypertension, the stubborn kind that stays high even on three medications, 26.9% on semaglutide had their medication stepped down, compared with 3% on placebo.2
Consider what that does to the average. Imagine you were trying to measure how much a man's load had lightened on a long walk, but every mile or so a helpful friend quietly removed a stone from his pack and put it in his own. You would weigh the pack at the end and find it lighter, certainly, but not as much lighter as the walk alone had made it. When doctors cut back the medication of the very people whose pressure is falling, the drop that shows up on paper is smaller than the real effect. The reviewers of the pooled analysis made the same point.2
Those medication changes were made by trial physicians who were watching their patients closely. They are not a license to start cutting your own pills. If your readings are trending down, the right thing is to keep a log and take it to whoever prescribes your blood pressure medication, and let them decide. Stopping some medications on your own, beta-blockers in particular, can cause trouble of its own.
Feeling Dizzy? The Low Blood Pressure Side
Lower is usually what we want, but a GLP-1 can bring several causes of low pressure together at once.
Suppose you have been on the same blood pressure medication for years, dosed for the weight you used to carry. It is rather like a furnace set in January and still running in April. Now you have lost 25 pounds, you are eating a good deal less, and in some weeks the nausea means you are drinking less water than you should. Any one of those things can lower your pressure. All three together, on a medication sized for a heavier you, can leave you lightheaded when you stand, tired in a way that does not feel like ordinary tiredness, or woozy after a workout.
That feeling ought to be reported to your provider. It usually means your medication needs adjusting, your fluids need attention, or both. Dehydration from stomach side effects carries risks of its own, which the semaglutide prescribing information flags in connection with kidney function.7 Our guide to managing GLP-1 side effects covers the nausea side of this, and we go further into the kidney question in our post on GLP-1s and kidney health.
If you ever faint, have chest pain, or feel your heart racing along with the dizziness, do not save it for your next check-in. Call a doctor that day or go to urgent care.
Heart Rate Goes the Other Way
There is one small movement in the opposite direction. While blood pressure tends to come down, resting heart rate tends to go up a little. In the tirzepatide monitoring study, heart rate rose by 2.1, 2.3, and 5.4 beats per minute over placebo at the 5, 10, and 15 mg doses.3 Semaglutide's prescribing information lists a similar small increase, a mean of 1 to 4 beats per minute.7
For most people this is a change you would only notice on a smartwatch. If you do watch your resting heart rate closely, it is better to expect it than to be alarmed by it. A resting rate that stays fast, or comes with palpitations, is worth mentioning to your provider.
How We Handle It at Defiant
A great many of the people who come to us in Lisle for weight loss are already taking a blood pressure medication, and that does not rule anyone out. What it does mean is that the medication list matters from the very first day.
Every Custom GLP-1 Protocol starts with a $50 consultation, where a provider goes through your history and current medications, along with lab orders you complete through your primary care doctor or Rythm Health. From there, dosing moves on a bi-weekly titration schedule with nurse check-ins between visits. Checking in between titrations means a stretch of dizziness or a run of low home readings gets noticed in days, instead of waiting for a quarterly appointment. A monthly Styku 3D body scan tracks whether the weight you are losing is fat rather than muscle.
If you check your blood pressure at home, bring those readings to your consult. They are among the most useful things you can hand a provider, and they are the numbers your prescribing doctor will want to see as your weight changes. Programs start from $295/mo, and you can see everything included on our medical weight loss page. We serve Lisle, Naperville, Downers Grove, Wheaton, and the rest of Chicago's western suburbs.
- Research suggests GLP-1 medications may lower systolic blood pressure by about 5 mmHg on average compared with placebo, with a 24-hour monitoring study of tirzepatide showing 7.4 to 10.6 mmHg.
- Most of the drop follows the weight loss. Adjusting for weight change shrank the semaglutide effect to about 1 mmHg, and weight explained roughly 70% of the tirzepatide effect.
- The average probably understates the real effect, because people on semaglutide were about twice as likely to have their blood pressure medication reduced during the trials.
- GLP-1s are not FDA-approved to treat hypertension. Any change to a blood pressure medication should come from your prescriber.
- Lower blood pressure, eating less, and dehydration from stomach side effects can combine to cause lightheadedness, which is worth reporting instead of pushing through.
- Resting heart rate tends to rise a few beats per minute on these medications.
Frequently Asked Questions
Want Your Numbers Moving in the Right Direction?
Weight, blood pressure, and body composition tend to move together, and it is easier to steer them when someone is watching all three. A $50 consultation at Defiant in Lisle starts with your history, your medications, and your labs, then builds a Custom GLP-1 Protocol with bi-weekly titration and nurse check-ins around them.
Keep Reading
Last updated September 26, 2026.
References
- Wilding JPH, Batterham RL, Calanna S, et al; STEP 1 Study Group. Once-Weekly Semaglutide in Adults with Overweight or Obesity. N Engl J Med. 2021;384(11):989-1002. PubMed
- Kennedy C, Hayes P, Cicero AF, et al. Semaglutide and blood pressure: an individual patient data meta-analysis. Eur Heart J. 2024;45(38):4124-4134. PubMed
- de Lemos JA, et al. Tirzepatide Reduces 24-Hour Ambulatory Blood Pressure in Adults With Body Mass Index ≥27 kg/m²: SURMOUNT-1 Ambulatory Blood Pressure Monitoring Substudy. Hypertension. 2024;81(4):e41-e43. PubMed
- Neter JE, Stam BE, Kok FJ, Grobbee DE, Geleijnse JM. Influence of weight reduction on blood pressure: a meta-analysis of randomized controlled trials. Hypertension. 2003;42(5):878-884. PubMed
- Blood Pressure Lowering Treatment Trialists' Collaboration. Pharmacological blood pressure lowering for primary and secondary prevention of cardiovascular disease across different levels of blood pressure: an individual participant-level data meta-analysis. Lancet. 2021;397(10285):1625-1636. PubMed
- Fryar CD, et al. Hypertension Prevalence, Awareness, Treatment, and Control Among Adults Age 18 and Older: United States, August 2021–August 2023. NCHS Data Brief No. 511. National Center for Health Statistics; 2024. CDC NCHS
- U.S. Food and Drug Administration. Semaglutide injection 2.4 mg prescribing information, Sections 5.5, 5.9, and 6.1. Revised 2026. FDA label