Most people know Wegovy and Ozempic as weight-loss medications. But research from recent years suggests that semaglutide and tirzepatide may have a far greater impact: they appear to protect the heart — regardless of how much weight you lose.

In this article, we review what the most important studies show, why GLP-1 medications affect the heart, and what it means for you.

What is GLP-1, and why does it affect the heart?

GLP-1 receptors are not only found in the stomach and brain — they are also present in the heart and blood vessels. When medications like semaglutide (Wegovy, Ozempic) or tirzepatide (Mounjaro) activate these receptors, several things happen at once: blood sugar drops, appetite is suppressed — and the heart is directly affected.

This is why researchers began investigating whether GLP-1 medications could not only help with weight but actually prevent heart attacks and strokes.

The SELECT trial: the major breakthrough

In 2023, the New England Journal of Medicine published the results of the SELECT trial — one of the largest studies ever conducted on GLP-1 medications and heart health. The trial followed 17,604 adults with overweight or obesity and existing cardiovascular disease, but without diabetes.

The result was striking: people who received semaglutide 2.4 mg weekly had a 20% lower risk of major adverse cardiovascular events — meaning heart attack, stroke, or death from cardiovascular causes — compared to those who received placebo. And the effect was present regardless of how much weight participants lost.

This means that something beyond just weight loss is protecting the heart — the medication appears to have direct cardioprotective properties.

SUSTAIN-6: semaglutide and type 2 diabetes

Even before the SELECT trial, the SUSTAIN-6 study had shown that semaglutide reduced the risk of major cardiovascular events by 26% in patients with type 2 diabetes and high cardiovascular risk. This was a key step, as it showed that the benefit was not limited to one specific group.

What about tirzepatide (Mounjaro)?

Tirzepatide — the active ingredient in Mounjaro — is somewhat newer, but the results point in the same direction. A large real-world analysis presented at the American Heart Association's Scientific Sessions in 2025 compared semaglutide and tirzepatide. Both medications significantly reduced the risk of heart attack, stroke, and death in people with obesity and diabetes.

Specifically, tirzepatide reduced the combined risk of heart attack, stroke, and death by 13% compared to another diabetes medication (dulaglutide), while semaglutide reduced the risk of stroke and heart attack by 18% compared to sitagliptin.

How do GLP-1 medications protect the heart?

Researchers don't fully agree on all the mechanisms, but several factors are at play:

1. Lower blood pressure

GLP-1 medications lower systolic blood pressure by an average of 2–4 mmHg. That may sound modest, but even small reductions in blood pressure reduce the risk of heart disease over time.

2. Improved cholesterol and blood fats

Treatment leads to modest reductions in LDL cholesterol (the "bad" cholesterol), total cholesterol, and triglycerides. These improvements contribute to a healthier cardiovascular system.

3. Reduced inflammation

Chronic low-grade inflammation is one of the most important risk factors for cardiovascular disease. GLP-1 medications dampen inflammatory markers such as CRP (C-reactive protein), TNF-α, and interleukin-6. These improvements occur partly independently of weight loss.

4. Direct effects on the heart and vessels

GLP-1 receptors in the heart muscle and blood vessels can be directly activated by the medication, improving the heart's pumping function and promoting a healthier vascular tone. Research suggests these direct effects contribute to the overall cardioprotective picture.

5. Weight loss and improved insulin sensitivity

Finally, weight loss still plays a role. While the direct cardiac effects are important, a reduction in body weight improves insulin sensitivity and reduces the workload on the heart.

Who benefits most?

Research suggests that those who already have cardiovascular disease gain the greatest benefit from GLP-1 treatment from a cardiac perspective. But even in people without existing heart disease, the risk profile improves with weight loss, lower blood pressure, and better blood lipids.

If you have high blood pressure, high cholesterol, type 2 diabetes, or have previously had a heart attack or stroke, GLP-1 medications may be particularly relevant — talk to your doctor about what applies to you.

What GLP-1 medications are not

It is important to emphasise that GLP-1 medications are not a guarantee against heart disease. They reduce risk statistically — but they do not replace a healthy diet, exercise, quitting smoking, and other lifestyle changes. They are also not the right choice for everyone: pregnancy, certain past cancers, and other conditions may mean the medication is not suitable.

The decision to start, continue, or stop treatment should always be made in consultation with your doctor.

What does this mean for your treatment?

Many people start Wegovy or Ozempic primarily to lose weight. That is a perfectly valid goal — but it is worth knowing that you may also be giving your heart a helping hand. This is one of the reasons GLP-1 medications are increasingly recommended for people with obesity and cardiovascular risk factors, even when weight loss is not the primary goal.

Whatever your reason for treatment: use the medication correctly, follow your doctor's dosing instructions — and use tools like ClickDose to ensure you inject exactly the amount you should.

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