A medication taken by millions weekly for diabetes and obesity shows an unexpected additional benefit: semaglutide, the active ingredient in Ozempic and Wegovy, reduces asthma attacks by nearly 40 percent and COPD flare-ups by roughly 20 percent. Four studies with over 20,000 participants each, presented at the European Respiratory Congress (ERS) in Barcelona in September 2026, provide the strongest evidence yet from real-world clinical practice.
Asthma and COPD: four million patients without adequate options
In Germany, more than 4.6 million statutory health insurance members over age 40 carry a diagnosis of asthma or COPD; estimates suggest up to eight million adults suffer from asthma. Both diseases are chronic and current therapies often provide incomplete control. Corticosteroids, bronchodilators, and biological antibody therapies do not reach sufficient effect in all patients. Many continue to experience acute episodes despite treatment, causing hospitalizations, work loss, and lasting lung damage.
What makes the new research particularly significant: it involves no new drug. Semaglutide is already available worldwide to millions of people treated for obesity or type 2 diabetes. If the findings hold up in clinical trials, these patients could simultaneously benefit from a respiratory advantage without additional medication.
How GLP-1 drugs work in the lungs
Semaglutide belongs to the class of GLP-1 receptor agonists, named after the body's own hormone glucagon-like peptide-1. Originally developed to regulate blood sugar and dampen appetite, this drug class shows growing evidence of additional effects: studies already demonstrate reduced heart attack and kidney risk in certain patient groups.
Its action on airways works through several mechanisms. GLP-1 receptors are found not only in the digestive system and brain but also in lung tissue. Lab studies show that GLP-1 agonists suppress inflammatory messengers called cytokines, which are central to asthma and COPD development, including mucus production, bronchospasm, and tissue damage. Weight loss also improves lung function in overweight patients by reducing mechanical pressure on the diaphragm.
That semaglutide showed stronger effects than other GLP-1 drugs suggests that weight loss alone does not account for the respiratory benefit, but rather molecule-specific properties of semaglutide itself may play a role.
What four studies with 20,000 to 22,000 participants each show
The research team led by Professor Chloe Bloom from the National Heart and Lung Institute at Imperial College London analyzed British electronic health records from real-world clinical practice. In four parallel analyses, between 20,000 and 22,000 adults were examined who started either a GLP-1 drug or a sulfonylurea, another commonly prescribed diabetes class.
The result: under semaglutide, there were nearly 40 percent fewer asthma attacks and roughly 20 percent fewer COPD flare-ups. Results were presented at the ERS congress by Dr. Bohee Lee.
Because these are observational data, direct causality cannot be proven. Participants were not randomly assigned and other differences between groups could influence outcomes. Researchers emphasize that the data provide no basis for changing prescription practices outside existing guidelines for obesity and diabetes.
In comparison: how strong other asthma drugs work
Biological drugs like dupilumab (Dupixent) or mepolizumab are approved specifically for severe asthma and reduce flare-ups in clinical trials by 20 to over 70 percent depending on patient group. However, they are expensive, require regular injections, and are available only to patients with specific inflammatory profiles such as eosinophilic asthma.
The pattern of unexpected additional benefits in already-approved drugs is not new. Metformin, one of the oldest available diabetes medications, shows hints in studies of reduced cancer risk. Acetylsalicylic acid, originally a painkiller, became standard in heart attack prevention. GLP-1 drugs could follow a similar trajectory.
The key difference from biologics: semaglutide is already taken by millions worldwide today. If the respiratory effect holds up in randomized trials, an ongoing therapy regimen could simultaneously prevent lung disease without new prescription or new medication.
If GATA-3 succeeds: approval for asthma could be possible by 2033
The next step is a targeted clinical trial. The GATA-3 protocol (NCT05254314) specifically investigates GLP-1 agonists in obese patients with symptomatic asthma in a randomized, controlled design. It is the first study to directly test the respiratory effect independent of weight loss.
With successful replication in GATA-3 and subsequent approval trials, realistic timelines at the EU regulatory authority EMA would be seven to ten years, so 2033 to 2036 at earliest. People who already take semaglutide for diabetes or obesity and also have asthma or COPD could benefit from a respiratory advantage today.