Semaglutide for heart failure with reduced ejection fraction: what the evidence shows

What the STEP-HFrEF trial actually found

The most directly relevant evidence comes from the STEP-HFrEF trial, a phase 3 randomised controlled study that enrolled adults with heart failure with reduced ejection fraction (left ventricular ejection fraction below 45%) and a BMI of 30 or above. Participants received semaglutide 2.4 mg weekly or placebo for 52 weeks alongside standard heart failure therapy.

The results, published in the New England Journal of Medicine, showed that people in the semaglutide group had greater reductions in the Kansas City Cardiomyopathy Questionnaire (KCCQ) score (a validated measure of heart failure symptoms and physical limitations) compared with placebo. They also lost substantially more body weight and walked further in six-minute walk tests. These are patient-centred outcomes that matter in day-to-day life, not just numbers on a scan.

Importantly, our page on semaglutide and heart failure covers the detail of why semaglutide did not cause harm to cardiac function in this population, with safety outcomes broadly consistent with what is known from the wider semaglutide programme. That said, the trial was not powered to assess hard cardiovascular endpoints like hospitalisation rates or mortality in HFrEF specifically, and those questions remain under investigation.

The STEP-HFpEF trials (covering heart failure with preserved ejection fraction) showed similarly positive symptom findings, but HFrEF and HFpEF are distinct conditions with different underlying mechanisms, so their results are not interchangeable.

How Wegovy's UK licence relates to heart failure

Wegovy's UK marketing authorisation, granted by the MHRA, covers two indications: weight management in adults with obesity or overweight and a weight-related condition, and reduction of major adverse cardiovascular events (heart attack, stroke, cardiovascular death) in adults with established cardiovascular disease and BMI of 27 or above. You can read more about the general Wegovy approval on our Wegovy overview page.

Heart failure with reduced ejection fraction is not itself a named indication under either licence. The cardiovascular indication was driven largely by the SELECT trial, which showed a reduction in major adverse cardiovascular events, a different outcome measure from the symptom and quality-of-life endpoints assessed in STEP-HFrEF.

This distinction matters in practice. A prescriber reviewing your case will look at why semaglutide is being considered (weight management? cardiovascular risk reduction?) and whether your HFrEF diagnosis or the medicines you take for it affect suitability. Some heart failure medications (including certain diuretics and digoxin) require monitoring when gastrointestinal side effects from GLP-1 treatment could affect fluid balance or drug levels, and anyone wanting to understand how the treatment affects the body more broadly may find our page on Wegovy and liver function a useful part of that picture. That conversation belongs with your cardiologist and prescriber together, not a checklist.

For context on how semaglutide interacts more broadly with the heart, our page on semaglutide and heart health covers the cardiovascular evidence in full.

Practical considerations for people with HFrEF asking about Wegovy

If you have HFrEF and obesity, the weight-loss evidence is genuinely encouraging, excess weight worsens cardiac workload, and even modest sustained loss can reduce symptoms. Semaglutide's effects on appetite and gastric emptying can make weight loss more achievable than diet alone for many people. That is the honest position.

The practical questions are around safety monitoring. GLP-1 medicines commonly cause nausea, reduced appetite and, in some people, vomiting, effects that can temporarily reduce fluid and calorie intake. In someone on diuretics or with already-compromised renal function (common in HFrEF), that matters. The NHS semaglutide medicines page lists the key side effects and interactions to be aware of.

One checking habit worth doing before any consultation: pull out your current heart failure medication list (including doses) and note your most recent ejection fraction figure if you have it from a recent echocardiogram. A prescriber can review interactions far more precisely with that information to hand, and it takes about 60 seconds to photograph the relevant letters.

People with HFrEF are not automatically excluded from semaglutide treatment, but the assessment is necessarily more detailed. Our clinical team reviews each consultation individually, there is no algorithm making the call. If you want to explore whether Wegovy is appropriate with your heart failure diagnosis, a structured clinical conversation is the right starting point. The STEP-HFrEF trial background gives a fuller read of the evidence if you want to arrive at that conversation well-prepared.

For a broader look at treatment options, our weight loss treatments overview outlines what is currently licensed in the UK and how private prescribing works.