BARCELONA, Spain – People taking semaglutide had fewer asthma exacerbations in a large real-world analysis of UK medical records, with the strongest association seen among patients with asthma, according to research presented at the European Respiratory Society Congress.
Researchers led by Imperial College London’s National Heart and Lung Institute compared people starting semaglutide and other GLP-1 receptor agonists with patients beginning sulfonylurea diabetes medicines. The semaglutide analysis included 22,537 new users.
Semaglutide use was associated with a 24% lower hazard of airway exacerbations compared with sulfonylureas overall. Among patients with asthma, the association was substantially stronger, with a weighted hazard ratio of 0.20, corresponding to an approximately 80% lower hazard in that analysis.
The researchers also reported an association with about a 20% reduction in COPD flare-ups.
The findings do not establish that semaglutide itself prevented the attacks. The study was observational, meaning researchers examined patterns in existing medical records rather than randomly assigning patients to receive semaglutide or another treatment.
Semaglutide showed the strongest signal
The research examined several GLP-1 receptor agonists, a class of medicines widely used to treat type 2 diabetes and, increasingly, obesity.
Semaglutide stood out from the other drugs studied. Researchers did not find statistically significant reductions in airway exacerbations associated with liraglutide, dulaglutide or exenatide. The semaglutide results also showed a stronger association at higher doses, although the confidence interval for the medium- and high-dose analysis was wide.
Researchers said the findings add to earlier evidence suggesting that GLP-1 medicines could influence respiratory outcomes. Possible explanations include effects related to inflammation, metabolic health and obesity, which can worsen asthma severity.
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The study was designed to examine whether respiratory outcomes differed among people already receiving treatment for conditions such as diabetes or obesity. It was not designed to determine whether semaglutide should be prescribed specifically as an asthma treatment.
Experts caution against interpreting the findings as proof
The distinction between association and causation is important.
Marie Spreckley, a researcher at the University of Cambridge who commented on the study through the Science Media Centre, said the observational design could not establish that semaglutide caused the lower rate of asthma attacks. She described the research as potentially important real-world evidence but said the headline claim that semaglutide “can reduce” asthma attacks was not supported by the study design.
Patients taking semaglutide can differ from comparison groups in ways that are difficult to completely account for, even when statistical methods are used to balance characteristics such as body mass index, smoking, disease severity and other medical conditions.
The researchers used doubly robust inverse probability weighting to address potential differences between treatment groups. Even so, residual confounding cannot be ruled out in an observational study.
The findings do not change asthma treatment guidance
Semaglutide is already approved for specific uses involving type 2 diabetes and weight management, but the new findings do not establish it as an asthma treatment.
The researchers said people with asthma or COPD who are already eligible for GLP-1 therapy because of obesity or diabetes could potentially gain additional respiratory benefits, but they called for future clinical trials to test that possibility directly.
The broader safety evidence is also still developing. A 2026 systematic review of respiratory outcomes associated with GLP-1 receptor agonists found mixed evidence across different study designs and emphasized that pharmacovigilance signals do not establish causality.
The latest study therefore adds to an emerging research area rather than providing a basis for changing asthma care.
If randomized trials confirm that semaglutide or related medicines directly reduce exacerbations, the finding could expand understanding of how metabolic treatments interact with respiratory disease. For now, the evidence shows an association that warrants further investigation.
Reporting Credit: European Respiratory Society — conference presentation and study findings; Imperial College London National Heart & Lung Institute — research leadership and analysis; Science Media Centre — independent expert assessment of the observational evidence.
