Which GLP-1 Is Best for Cardiovascular Benefit? What the Two Big Trials Actually Showed
Short answer
On the evidence that exists today, semaglutide. It is the only GLP-1 with a large placebo-controlled trial showing fewer heart attacks, strokes and cardiovascular deaths in people with obesity who do not have diabetes: SELECT found a 20% reduction in major adverse cardiovascular events.1
Tirzepatide has a cardiovascular outcomes trial too, but it was run in people with type 2 diabetes against another GLP-1 (dulaglutide) rather than placebo, and it showed tirzepatide was not worse — not that it was better.2 That is a real result, but it is a different and weaker claim.
This is not medical advice. Tirzeptides is an independent comparison site, not a healthcare provider. Nothing here creates a doctor-patient relationship or replaces a conversation with a licensed clinician. GLP-1 medications are prescription drugs with real risks and contraindications. Talk to a qualified provider before starting, stopping or changing any treatment.
What SELECT showed for semaglutide
SELECT enrolled 17,604 adults aged 45 and over with a BMI of 27 or more and established cardiovascular disease, and specifically excluded people with diabetes. Half received weekly semaglutide 2.4 mg, half placebo, for a median of about 40 months.
The primary result: a 20% relative reduction in the composite of cardiovascular death, non-fatal heart attack and non-fatal stroke.1 Later analyses found the benefit was not simply explained by how much weight people lost, which is why cardiologists treat it as a drug effect rather than only a weight effect.3
That trial is the reason Wegovy carries an FDA indication for reducing cardiovascular risk in adults with obesity and heart disease. No other weight-loss GLP-1 has that indication as of the date on this page.
What SURPASS-CVOT showed for tirzepatide
SURPASS-CVOT compared tirzepatide with dulaglutide — itself a GLP-1 with proven cardiovascular benefit — in people with type 2 diabetes and established cardiovascular disease, over a median of four years.
The primary endpoint occurred in 12.2% of the tirzepatide group and 13.1% of the dulaglutide group, a hazard ratio of 0.92. That met the pre-specified bar for non-inferiority (tirzepatide is at least as good as dulaglutide) but did not reach statistical superiority.2 All-cause mortality, kidney measures and HbA1c looked better with tirzepatide, but those comparisons were not adjusted for multiple testing, so they are supportive rather than conclusive.
Two things follow. First, tirzepatide clearly does not harm the heart and very probably protects it at least as well as an established GLP-1. Second, there is still no placebo-controlled cardiovascular trial of tirzepatide in people with obesity and no diabetes, which is the population most people asking this question are in.
Bodybuilding Health+
Clearest pricing ladder · scored 8.0/10
Save $480 a year on a 12-month plan
- Clear tiered pricing published for every bundle length
- Microdosing protocols available for people who want lower doses
- Wide catalogue: NAD+ and sermorelin from $129/mo, PT-141, glutathione, GHK-Cu
Why the comparison is not apples to apples
- Different populations. SELECT: obesity, heart disease, no diabetes. SURPASS-CVOT: type 2 diabetes with heart disease.
- Different comparators. SELECT compared against placebo. SURPASS-CVOT compared against an active drug that already reduces cardiovascular events, so a null result there is far more impressive than a null result against placebo would be.
- Different questions. SELECT asked whether semaglutide beats nothing. SURPASS-CVOT asked whether tirzepatide is at least as good as dulaglutide.
Anyone who tells you one drug is definitively better for your heart than the other is going beyond what the trials can support. What can be said is that semaglutide has the direct evidence in the obesity-without-diabetes population, and tirzepatide has strong indirect evidence plus larger weight loss.
What this means for compounded versions
All of the above applies to the FDA-approved products used in the trials. Compounded semaglutide and tirzepatide are not FDA-approved, were not used in SELECT or SURPASS-CVOT, and are not reviewed for potency or purity by the FDA. You should not assume trial-level cardiovascular benefit transfers to a compounded preparation. If cardiovascular protection is the reason you are considering a GLP-1, that is a conversation to have with a prescriber about the approved product, not a comparison-shopping decision.
Where compounded medication fits, and what it costs, is covered in compounded vs brand-name GLP-1 and the price index.
The short version
Semaglutide is the GLP-1 with proven, placebo-controlled cardiovascular benefit in people with obesity, and it has the FDA indication to show for it. Tirzepatide is at least as good as an established GLP-1 in diabetics, produces more weight loss, and has not yet been tested against placebo for heart outcomes in the obesity population. If the heart is the priority, the evidence currently favours semaglutide; if weight loss is the priority, tirzepatide leads. Neither conclusion applies to compounded products.
Sources
- SELECT: Semaglutide Reduces Risk of MACE in Adults With Overweight or Obesity — American College of Cardiology
- SURPASS-CVOT Published: Large Trial Confirms CVD Efficacy of Tirzepatide — TCTMD / Cardiovascular Research Foundation
- Semaglutide and cardiovascular outcomes by baseline and changes in adiposity measurements: a prespecified analysis of the SELECT trial — The Lancet
Our top three, compared
Ranked by the six published weights on how we rank. All three are paid partners.
Related questions
- Which GLP-1 is best for weight loss?
- What does GLP-1 do in the body?
- How long do GLP-1 side effects last?
- How fast does GLP-1 weight loss happen?
- Does compounded GLP-1 need to be refrigerated?
All GLP-1 questions answered → · GLP-1 price index → · Compare the 8 providers →