Semaglutide protects the heart and works even in people who lost little weight. In the SELECT trial it lowered the risk of heart attack, stroke and cardiovascular death by 20 percent in 17,604 people with heart disease and excess weight. The risk of death from any cause fell by 19 percent. In people with heart failure the risk of heart attack, stroke and cardiovascular death fell by 28 percent. The protection did not depend on how many kilograms someone lost in the first months. Below are the results of SELECT and six analyses of this trial published from 2023 to 2026.
How was the SELECT trial run?
SELECT included 17,604 people aged 45 or over with overweight or obesity and a history of heart or blood vessel disease. None of the participants had diabetes. The trial was run in 41 countries at 804 centres, with a placebo group and without participants knowing what they received.
- Dose: semaglutide 2.4 mg once a week, reached gradually over 16 weeks.
- Participants: mean age 61.6 years, mean body mass index 33.4, men made up 72.3 percent.
- Follow-up: 39.8 months on average, more than 3 years.
- Main outcome: a first heart attack, stroke or death from cardiovascular causes.
Such an event affected 569 of 8,803 people on semaglutide, or 6.5 percent. On placebo it affected 701 of 8,801 people, or 8.0 percent. The results were published in the New England Journal of Medicine in 2023.
Does semaglutide reduce the number of deaths?
Yes, the risk of death from any cause was 19 percent lower on semaglutide than on placebo. An analysis of all 833 deaths in SELECT was published in 2024 in the Journal of the American College of Cardiology. 485 deaths had cardiovascular causes and 348 other causes.
| Type of death | Risk on semaglutide against placebo |
|---|---|
| Death from any cause | 19 percent lower |
| Death from non-cardiovascular causes | 23 percent lower |
| Death from infection | 62 against 87 cases, 29 percent lower |
| Death from cardiovascular causes | 15 percent lower, difference not statistically significant |
The trial ran during the pandemic, so the researchers also counted COVID-19. Semaglutide did not protect against the infection itself. Among people who fell ill, however, 43 died on semaglutide and 65 on placebo.
Does heart protection depend on how much weight is lost?
No, semaglutide protected the heart regardless of starting weight and of how much someone lost at the start. This was shown by a SELECT analysis published in The Lancet in November 2025. The researchers compared the risk in people who lost a lot, a little or no weight in the first 20 weeks.
Weight loss up to week 20 did not translate linearly into later risk of heart attack and stroke. Protection was similar across all ranges of weight and waist circumference at the start. The reduction in waist circumference explained about 33 percent of the benefit. The authors conclude that semaglutide acts on the heart through routes other than fat loss alone.
An analysis of blood sugar, measured as HbA1c, gave a similar result. Heart protection was the same in people with normal blood sugar and with prediabetes. It also did not depend on whether HbA1c fell in the first 20 weeks.
How does semaglutide act on inflammation?
Semaglutide lowered CRP, a marker of inflammation in the body, by 37.8 percent after two years. The result comes from a SELECT analysis published in September 2026 in the journal Circulation. At the start mean CRP was 1.96 mg/l in the semaglutide group and 1.91 mg/l in the placebo group.
The fall in CRP was already visible after 4 and 8 weeks, before weight had clearly fallen. It also appeared in people who did not lose weight at all. It did not depend on LDL cholesterol or on taking statins.
Higher CRP at the start meant a higher risk of heart attack, stroke and death. Semaglutide lowered this risk in all CRP groups. The authors concluded that less inflammation partly explains the heart protection in SELECT.
Does semaglutide help in heart failure?
Yes, in people with heart failure semaglutide lowered the risk of heart attack, stroke and cardiovascular death by 28 percent. SELECT included 4,286 such people, 24.3 percent of participants. The analysis was published in The Lancet in August 2024.
| Result in people with heart failure | Risk on semaglutide against placebo |
|---|---|
| Heart attack, stroke or cardiovascular death | 28 percent lower |
| Cardiovascular death, hospital stay or urgent visit for heart failure | 21 percent lower |
| Cardiovascular death | 24 percent lower |
| Heart attack, stroke or cardiovascular death with reduced ejection fraction | 35 percent lower |
| Heart attack, stroke or cardiovascular death with preserved ejection fraction | 31 percent lower |
The ejection fraction tells what share of the blood the heart pushes out with each beat. Semaglutide worked in both forms of heart failure, regardless of age, sex and weight. Serious adverse events occurred less often on it than on placebo.
How much weight is lost on semaglutide over 4 years?
After 4 years in SELECT body weight was 10.2 percent lower on semaglutide and 1.5 percent lower on placebo. Weight fell over the first 65 weeks and then stayed at that level until the end. The results were published in Nature Medicine in 2024.
- Waist circumference: minus 7.7 cm on semaglutide against minus 1.3 cm on placebo.
- Waist-to-height ratio: minus 6.9 percent against minus 1.0 percent.
- Serious adverse events: less frequent on semaglutide in every weight group.
Weight loss was clear in women and men, in all regions of the world and at every starting weight. How weight changes in the first months of treatment is shown in the guide on when semaglutide gives its first results. What happens to weight after stopping is described in the guide on semaglutide after the end of treatment.
What else does semaglutide do for the heart and blood vessels?
Semaglutide also lowers blood pressure, which in itself puts strain on the heart. The figures from blood pressure studies are collected in the guide on semaglutide and tirzepatide and blood pressure.
Kidney protection in the FLOW trial and tirzepatide results in heart failure are collected in the guide semaglutide and tirzepatide beyond weight loss. You will also find there the dates of the US FDA decisions for each indication.
Where to buy semaglutide?
The shop has semaglutide 3 mg Bio-Peptide for 90 EUR, in stock. How many weeks one vial lasts at the doses used in trials is calculated in the guide on how long a vial of semaglutide, tirzepatide and retatrutide lasts. Everything about this molecule is collected on the semaglutide page.
The product in the shop is material for laboratory research, not the medicine Wegovy or Ozempic. The SELECT trial was run with the approved medicine under medical supervision, and treatment of heart disease is a matter for a cardiologist.
Frequently asked questions
Does semaglutide protect the heart?
Yes. In the SELECT trial semaglutide 2.4 mg lowered the risk of heart attack, stroke and cardiovascular death by 20 percent in people with heart disease and excess weight, without diabetes.
Does heart protection depend on weight loss?
No. A 2025 SELECT analysis showed that protection was similar regardless of starting weight and of how much someone lost in the first 20 weeks.
Does semaglutide reduce the risk of death?
Yes. In SELECT the risk of death from any cause was 19 percent lower than on placebo. The clearest difference was in non-cardiovascular deaths, especially deaths from infection.
Can semaglutide be used in heart failure?
In SELECT, in 4,286 people with heart failure, the risk of heart attack, stroke and cardiovascular death fell by 28 percent, in both forms of heart failure.
How quickly does semaglutide lower inflammation?
The fall in CRP was already visible after 4 and 8 weeks, before weight had clearly fallen. After two years CRP was 37.8 percent lower.
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. https://doi.org/10.1056/NEJMoa2307563
- Scirica BM, Lincoff AM, Lingvay I et al. The Effect of Semaglutide on Mortality and COVID-19-Related Deaths: An Analysis From the SELECT Trial. Journal of the American College of Cardiology, 2024, 84(17): 1632-1642. https://doi.org/10.1016/j.jacc.2024.08.007
- 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. https://doi.org/10.1016/S0140-6736(25)01375-3
- Lingvay I, Deanfield J, Kahn SE et al. Semaglutide and Cardiovascular Outcomes by Baseline HbA1c and Change in HbA1c in People With Overweight or Obesity but Without Diabetes in SELECT. Diabetes Care, 2024, 47(8): 1360-1369. https://doi.org/10.2337/dc24-0764
- Plutzky J, Bogdański P, Colhoun HM et al. Effect of Semaglutide on the Inflammatory Biomarker High-Sensitivity CRP in Patients With Established Cardiovascular Disease and Overweight or Obesity in SELECT: A Prespecified Secondary Analysis. Circulation, 2026, 154(11): 976-991. https://doi.org/10.1161/CIRCULATIONAHA.125.074482
- Deanfield J, Verma S, Scirica BM et al. Semaglutide and cardiovascular outcomes in patients with obesity and prevalent heart failure: a prespecified analysis of the SELECT trial. The Lancet, 2024, 404(10454): 773-786. https://doi.org/10.1016/S0140-6736(24)01498-3
- Ryan DH, Lingvay I, Deanfield J et al. Long-term weight loss effects of semaglutide in obesity without diabetes in the SELECT trial. Nature Medicine, 2024, 30(7): 2049-2057. https://doi.org/10.1038/s41591-024-02996-7