Novo Nordisk reports Wegovy linked to 57% lower heart risk than tirzepatide in real-world analysis

A Novo Nordisk real-world analysis reported that Wegovy (semaglutide) was associated with a 57% lower risk of heart attack, stroke or death than tirzepatide in people with obesity and cardiovascular disease ^[1]. The company released the finding on August 31, 2025 ^[1].

Wegovy is a GLP-1 receptor agonist approved by the FDA in injection and tablet forms ^[1]. Its approved uses include reducing the risk of major adverse cardiovascular events — cardiovascular death, non-fatal heart attack or non-fatal stroke — in adults with established cardiovascular disease and either obesity or overweight ^[1]. The drug was first approved on June 4, 2021, for weight loss in adults with obesity, and the cardiovascular risk-reduction indication was added on March 8, 2024 ^[1].

The 57% figure comes from a real-world study, meaning researchers compared how patients fared in routine care instead of assigning each person by chance to one medicine or the other ^[1]. That kind of analysis can show an association between a drug and an outcome, but it cannot prove the drug caused the difference. Randomized trials, in which patients are assigned to a treatment by chance, remain the standard for showing cause and effect.

For context, the randomized SELECT trial found that semaglutide 2.4 mg reduced the risk of major adverse cardiovascular events by 20% in adults with overweight or obesity compared with placebo ^[1]. Those results were presented at the American Heart Association Scientific Sessions in November 2023 and published at the same time in the New England Journal of Medicine ^[1]. SELECT compared semaglutide with placebo, not with tirzepatide, so the 20% and 57% figures do not measure the same thing.

A separate analysis of SELECT data, released in May 2025, reported that the reduction in cardiovascular events was observed early, before patients had achieved clinically meaningful changes in body weight ^[1].

The August 31 announcement left key details out. It did not report how many people were included in the real-world analysis, how long they were followed, how the Wegovy and tirzepatide groups were defined, or which specific heart events were counted ^[1]. It also did not say whether the analysis has been published in a peer-reviewed journal or presented at a medical meeting ^[1]. Wegovy's label carries a boxed warning for an increased risk of thyroid C-cell tumors, along with warnings for pancreatitis, gallbladder disease and low blood sugar, among others ^[1].

Why it matters for patients

For people with obesity and established cardiovascular disease, the result is likely to be part of discussions about treatment options. The main practical point is what kind of evidence this is: a real-world association, not a randomized comparison. The strongest randomized evidence that semaglutide lowers heart risk in this population comes from SELECT, which measured a 20% reduction against placebo ^[1].

No randomized trial has directly compared Wegovy and tirzepatide on heart outcomes, and the analysis released on August 31 does not say whether the two drugs differ for any individual patient ^[1]. Details that would help patients and clinicians judge the finding — such as how many people were studied and how the groups were put together — have not been disclosed ^[1].

The analysis does not address what happens when someone switches from one of these medicines to the other, and it does not change Wegovy's FDA-approved uses ^[1]. Tirzepatide's approved uses are not described in the announcement ^[1].

What happens next

No date has been reported for publication of the full analysis in a peer-reviewed journal or for presentation at a medical conference ^[1]. No randomized trial that assigns patients to Wegovy or tirzepatide and tracks heart outcomes has been announced ^[1].