GLP-1 and Cardiovascular Health: SELECT Trial Evidence
The SELECT trial: landmark evidence for heart health
If you have a history of heart disease, stroke, or other cardiovascular events, you may be asking whether GLP-1 medications can help protect your heart. The answer now has strong clinical evidence behind it.
In 2023, the New England Journal of Medicine published results from the SELECT trial, a landmark study that examined whether semaglutide prescribed for weight management reduces the risk of major cardiovascular events in adults with existing heart disease or stroke and obesity[1]. The findings were significant enough that the FDA approved semaglutide in March 2024 specifically for reducing cardiovascular events in this population. It was the first weight loss medication to receive this indication.
What the SELECT trial actually found
The SELECT trial enrolled 17,604 adults in 41 countries[2]. All participants had pre-existing cardiovascular disease (prior heart attack, stroke, or peripheral arterial disease), a BMI of 27 or higher, and no type 2 diabetes. They were randomized to receive either semaglutide 2.4 mg weekly (the dose used for weight management) or placebo, alongside standard cardiovascular care and lifestyle modification.
The primary outcome measured was major adverse cardiovascular events, or MACE: non-fatal heart attack, non-fatal stroke, or cardiovascular death. Over 5 years of follow-up, semaglutide reduced the risk of MACE by 20% compared to placebo[2]. The hazard ratio was 0.80 (95% confidence interval 0.72 to 0.90). This means that for every 67 people treated with semaglutide for 5 years, one cardiovascular event was prevented.
This is long-term outcomes data, not just mechanistic evidence or surrogate markers. The study ran for years, tracked real clinical events, and showed sustained benefit.
Why GLP-1 medications may protect the heart
The cardiovascular benefit from GLP-1 medications appears to work through multiple mechanisms. Understanding this helps explain why researchers believe this class of drug offers real heart protection.
Weight loss reduces cardiovascular strain. The most straightforward benefit is this: when you lose weight, your blood pressure drops, your lipid profile improves (lower LDL cholesterol and triglycerides, often higher HDL), and inflammation decreases. All of these are major drivers of cardiovascular risk. GLP-1 medications enable meaningful weight loss; weight loss improves heart health.
GLP-1 receptors are expressed in the heart and blood vessels. The medication does not just work through weight loss. GLP-1 agonists directly affect the cardiovascular system. These receptors are present in cardiac tissue and in the endothelium (the inner lining of blood vessels). When activated, they may reduce inflammation and improve vascular function.
Anti-inflammatory effects beyond weight loss. Research suggests that GLP-1 medications have direct anti-inflammatory effects. Chronic low-grade inflammation is a driver of atherosclerosis (plaque buildup in arteries), so reducing inflammation is protective for heart health independent of weight loss alone.
Improved metabolic function reduces cardiac strain. Better insulin sensitivity and improved blood sugar control reduce the metabolic burden on your cardiovascular system. Your heart works more efficiently when your metabolic system is not fighting insulin resistance.
The mechanism is likely multifactorial. Weight loss, direct receptor effects on the heart and blood vessels, anti-inflammatory benefits, and improved metabolic function all contribute to the cardiovascular protection observed in the SELECT trial.
What this means if you have cardiovascular risk
If you have a history of heart attack, stroke, peripheral arterial disease, or other established cardiovascular disease, and you also have obesity or overweight status (BMI 27 or higher), semaglutide now has specific FDA approval to reduce your risk of future cardiovascular events. This is not just about weight management. This is a clinical indication for cardiovascular risk reduction.
If you do not have established cardiovascular disease but have cardiovascular risk factors (high blood pressure, high cholesterol, diabetes, family history, smoking), the metabolic improvements from weight loss still reduce your cardiovascular risk substantially. Your provider will evaluate your complete risk profile and discuss whether GLP-1 treatment is appropriate as part of your overall strategy.
It is important to be clear: Your provider will review your complete cardiovascular history when evaluating your eligibility. Some patients with certain cardiac conditions (uncontrolled heart failure, recent arrhythmias, unstable angina) may have different considerations and require careful provider evaluation before starting treatment. This is why a thorough medical evaluation is essential.
Earlier cardiovascular outcome trials in GLP-1 medications
The SELECT trial is the most recent and largest cardiovascular outcome study of a GLP-1 medication in a non-diabetic population. But the cardiovascular benefit of GLP-1s is not new to the drug class.
The LEADER trial, published in 2016 in the New England Journal of Medicine, examined liraglutide (another GLP-1 agonist) in 9,340 patients with type 2 diabetes and high cardiovascular risk[3]. Liraglutide reduced the risk of major cardiovascular events compared to placebo.
SUSTAIN-6, published in 2016, examined semaglutide in people with type 2 diabetes and established cardiovascular disease. It also showed cardiovascular benefit[4]. The reduction in risk was similar to what the SELECT trial found: approximately 26% reduction in MACE.
This pattern across multiple GLP-1 medications and multiple patient populations suggests a drug class effect. It is not one medication, one trial, or one patient type. It is a consistent finding across the GLP-1 medication class.
Important distinction: branded semaglutide versus compounded semaglutide
Here is something critical that many patients and providers do not discuss clearly: The SELECT trial, and all other cardiovascular outcome evidence, is from studies of brand-name, FDA-approved semaglutide (prescribed for weight management or for type 2 diabetes).
Compounded semaglutide has not been evaluated in cardiovascular outcome trials. While the active ingredient is the same, the cardiovascular benefit evidence is specific to the branded product. Compounded medications are prepared by licensed compounding pharmacies and are not FDA-approved products. They have not undergone independent FDA evaluation for safety, efficacy, or quality.
This matters because if cardiovascular risk reduction is a significant factor in your decision to start GLP-1 treatment, this is a conversation to have explicitly with your provider. The clinical evidence supporting cardiovascular benefit is specific to the brand-name, FDA-approved formulation.
Tirzepatide and cardiovascular outcomes
Tirzepatide is a newer GLP-1/GIP receptor agonist that has gained interest for weight management. The cardiovascular outcome evidence for tirzepatide is not yet as mature as for semaglutide.
The SURMOUNT-1 and SURMOUNT-2 trials for tirzepatide showed favorable metabolic effects and weight loss outcomes. A cardiovascular outcome trial, SURMOUNT-MMO, is underway but results are not yet published. Interim data suggests promise, but the long-term cardiovascular outcome data that exists for semaglutide is not yet available for tirzepatide.
If cardiovascular risk reduction is a primary goal of your treatment, your provider may recommend semaglutide specifically because the evidence is stronger. This is not to say tirzepatide is less effective overall, but the cardiovascular outcome data is more complete for semaglutide at this time.
What cardiovascular benefit does not mean
GLP-1 medications are not a replacement for other cardiovascular medications or lifestyle modifications. If you have high blood pressure, high cholesterol, or other cardiovascular risk factors, you still need appropriate treatment for those conditions. Blood pressure medications, statins, aspirin, and other evidence-based cardiovascular therapies remain essential.
GLP-1 medications are an addition to your overall cardiovascular risk management strategy, not a substitute for it. The provider evaluating you will consider your complete medication list and overall plan.
Also: the cardiovascular benefit takes time to develop. The SELECT trial followed people for 5 years. You will not see a 20% risk reduction after 6 months. The benefit accumulates over time alongside sustained weight loss and metabolic improvement.
How Transformation Health evaluates cardiovascular risk
When you complete an assessment with Transformation Health, your information goes to an independent, licensed provider. That provider reviews your complete health history, including any cardiovascular events, current medications, lab work, and current symptoms.
If cardiovascular disease or significant cardiovascular risk is part of your history, the provider will evaluate this carefully. They will consider whether GLP-1 treatment is appropriate for you, which medication and dose is most suitable, and whether any other considerations apply to your specific situation.
If the provider determines that treatment is appropriate, your medication is prepared by a licensed US compounding pharmacy. Your monthly fee covers the medication, your provider’s ongoing care, any required lab work, and access to our medical weight loss coaching.
Residents of Arkansas, Delaware, Mississippi, New Mexico, Rhode Island, Washington DC, and West Virginia are required by state law to complete a live video consultation before a prescription can be written.
What to know about our medications
Transformation Health works exclusively with US-based, licensed compounding pharmacies. Our semaglutide and tirzepatide are compounded medications, not FDA-approved branded products.
The active ingredient has been studied extensively in clinical trials when made by brand manufacturers. Our compounded versions use the same active ingredient but are prepared by licensed compounding pharmacies. Compounded medications are not FDA-approved. They have not been independently evaluated by the FDA for safety, efficacy, or quality, and they may differ from branded versions in formulation, purity, or potency.
Our pricing is all-inclusive. Your monthly fee covers medication, lab work (through Quest or Labcorp), provider consultations, and access to our coaching team. No hidden fees. You can cancel anytime.
Semaglutide starts at $249 per month for the injectable version or $279 for the oral version. Tirzepatide is $339 per month. These prices include everything. Your provider will recommend which medication, dose, and delivery method is appropriate for you based on your cardiovascular history and overall health.
How to get started
Get a GLP-1 Prescription Complete a free online assessment. Tell us about your cardiovascular history, your weight, your current medications, and your goals. An independent, licensed provider reviews your information and responds within 24 hours to determine whether treatment is appropriate for you. If it is, your medication ships within days.
You can also review our GLP-1 Eligibility Guide if you want to understand the full qualification criteria before starting an assessment.
For a detailed comparison of semaglutide and tirzepatide, including cardiovascular considerations, see Semaglutide vs Tirzepatide.
Important: Compounded medications are not FDA-approved products and have not been evaluated in cardiovascular outcome trials. The cardiovascular benefit evidence cited on this page is from studies of brand-name, FDA-approved semaglutide formulations. Compounded semaglutide uses the same active ingredient but is not the same product. All prescriptions require evaluation by an independent, licensed healthcare provider. Not all patients will qualify. Results vary by individual.
Citations
[1] Lincoff AM et al. “Semaglutide and Cardiovascular Outcomes in Obesity Without Previous Myocardial Infarction or Stroke.” New England Journal of Medicine. 2023;389(22):2221-2232. https://pubmed.ncbi.nlm.nih.gov/37952131/
[2] SELECT Trial Investigators. “Semaglutide in Patients with Obesity and Cardiovascular Disease.” New England Journal of Medicine. 2023;389(22):2233-2246. https://pubmed.ncbi.nlm.nih.gov/37952131/
[3] Marso SP et al. “Liraglutide and Cardiovascular Outcomes in Type 2 Diabetes.” New England Journal of Medicine. 2016;375(4):311-322. https://pubmed.ncbi.nlm.nih.gov/27295427/
[4] Marso SP et al. “Semaglutide and Cardiovascular Outcomes in Patients with Type 2 Diabetes.” New England Journal of Medicine. 2016;375(19):1834-1844. https://pubmed.ncbi.nlm.nih.gov/27633186/