A major trial of semaglutide, the drug sold as Wegovy and, in a lower dose for diabetes, Ozempic, found it cut serious heart events by a fifth in people with obesity and existing heart disease. The twist most headlines missed is that the heart benefit did not seem to depend on how much weight people lost.

What you need to know

A large 2023 trial called SELECT tested weekly semaglutide against a placebo in 17,604 adults who had overweight or obesity and existing heart disease, but not diabetes. Over about three years, serious heart events fell by 20%. That is a real, important result in a real-world high-risk group.

The more interesting part came later. A 2025 analysis of the same trial found the heart benefit was largely independent of how much weight people actually lost. Only a small part of it tracked with a slimmer waist. The rest pointed to other effects of the drug.

So the takeaway is not really about weight. It is that these drugs are starting to look less like slimming aids and more like heart and metabolic medicines, for the people who need them.

What the study found

SELECT, published in the New England Journal of Medicine in 2023, randomised 17,604 adults with overweight or obesity and established cardiovascular disease, but no diabetes, to weekly semaglutide or a placebo, then followed them for roughly three years.

Serious heart events, meaning cardiovascular death, heart attack or stroke, fell by about 20%, from 8.0% on placebo to 6.5% on semaglutide (hazard ratio 0.80, 0.72 to 0.90).

Average weight loss was around 9 to 10%.

A 2025 prespecified analysis in The Lancet found the heart benefit was largely independent of how much weight people lost. Only about a third of it tracked with waist reduction, and the rest appeared to come through other routes.

Side effects were mostly gastrointestinal, and more people stopped the drug than the placebo, 16.6% versus 8.2%.

The researchers went as far as suggesting these drugs be thought of as disease-modifying treatments, not simply weight or blood-sugar drugs.

What to keep in perspective

The popular story is "miracle weight loss drug." That misses the actual finding, and a few cautions came along with it.

The heart benefit was not mainly about the pounds. The protection held even in people who lost little weight, which is the opposite of how it was usually reported.

It was tested in a specific group: people who already had heart disease and carried excess weight, without diabetes. The results do not automatically apply to healthy people taking it for longevity.

It is a drug, not a lifestyle. The side effects are real, and a meaningful share of people stopped taking it.

The benefit depends on staying on it. Weight, and the risk that comes with it, tends to return when people stop.

Rapid weight loss can include muscle as well as fat, which is why clinicians pair these drugs with protein and resistance training rather than weight loss alone.

The interesting finding was not the weight. It was that the heart benefit did not depend on it.

Why is this bigger than weight loss

For years, these drugs were studied mostly in people with diabetes, which made it hard to separate the heart benefit from the blood-sugar benefit. SELECT, run in people without diabetes, plus the weight analysis that followed, suggests the protection comes through several routes at once.

The likely mechanisms include:

Blood sugar and insulin

Blood pressure

Inflammation

Direct effects on the heart and blood vessels

That reframing matters because it points straight back to the markers underneath, the ones that carry cardiovascular risk whether or not someone is on the drug. For the full picture, see our complete guide to GLP-1s and longevity.

What this means for you

How to hold this if you are reading past the headlines:

If you have obesity and existing heart disease, this is genuinely good news, and a conversation to have with a doctor, not a decision to make from a headline.

If you are otherwise healthy and curious about it for longevity, the evidence does not stretch that far yet.

Whatever you decide, the useful move is to know the markers these drugs actually act on.

Knowing where your own risk sits is its own question, and a blood test answers a narrower one than people assume:

A routine blood test is designed to catch illness, reading your results against ranges set wide enough to flag disease across a whole population.

That is a different job from showing where your metabolic risk actually sits.

The markers that drive cardiovascular risk, blood sugar, inflammation, blood pressure and blood lipids, are exactly what a comprehensive panel surfaces. The drug is one lever, for a specific group. Your markers tell you where you are starting from.

See what a full Axo panel measures

A few questions worth answering

Does Ozempic help your heart even if you do not lose much weight? In the SELECT trial and its follow-up analysis, largely yes, in people who already had heart disease and excess weight. The benefit was mostly independent of how much weight they lost, which suggests the drug protects the heart through several routes, not slimming alone.

Is semaglutide the same as Ozempic and Wegovy? They are the same drug under different brands and doses. Wegovy is the higher-dose version for weight management, the one used in SELECT. Ozempic is the lower-dose version licensed for type 2 diabetes.

Should healthy people take it to live longer? The evidence does not support that yet. SELECT studied people with obesity and existing cardiovascular disease, not healthy people seeking longevity. It is a prescription medicine with real side effects, and a decision to make with a doctor.

What are the main downsides? Mostly gastrointestinal side effects, and more people stopped the drug than the placebo. The benefit also depends on staying on it, and rapid weight loss can include muscle as well as fat, which is why diet and strength work alongside it matter.

What markers does it affect? It acts on several at once, blood sugar, blood pressure, inflammation and lipids, which is likely why the heart benefit shows up beyond weight loss.

Sources

Lincoff AM, Brown-Frandsen K, Colhoun HM, et al. Semaglutide and Cardiovascular Outcomes in Obesity without Diabetes. New England Journal of Medicine. 2023;389(24):2221–2232. DOI: 10.1056/NEJMoa2307563. https://www.nejm.org/doi/full/10.1056/NEJMoa2307563

Deanfield J, Lincoff AM, Kahn SE, et al. Semaglutide and cardiovascular outcomes by baseline and changes in adiposity measurements: a prespecified analysis of the SELECT trial. The Lancet. 2025;406(10516):2257–2268. DOI: 10.1016/S0140-6736(25)01375-3. https://www.thelancet.com/journals/lancet/article/PIIS0140-6736(25)01375-3/fulltext

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