GLP-1 drugs and lung safety: what we know

A systematic review published in Cardiovascular Diabetology and Endocrinology Reports on 19 June 2026 examined pulmonary adverse events reported with GLP-1 receptor agonists across 19 studies covering randomised controlled trials, retrospective cohorts, pharmacovigilance databases and case reports. The headline finding: the respiratory safety profile of the class is neither uniformly benign nor alarming, but it is more complex than routine prescribing information suggests^[1].

What the review included

The authors followed PRISMA 2020 guidelines and searched PubMed, Embase and Scopus from inception through January 2026. They identified 19 studies: four randomised controlled trials (1,884 participants), five retrospective cohort studies (over 1.1 million participants), three pharmacovigilance analyses drawing on nearly 500,000 adverse-event reports, and seven case reports or case series involving 13 individual patients. The GLP-1 receptor agonists covered include semaglutide, liraglutide, dulaglutide, exenatide and lixisenatide^[1].

Common respiratory events: mild and comparable to controls

Upper respiratory tract infections were the most frequently reported pulmonary adverse event, appearing in eight of the twelve studies that tracked respiratory outcomes (66.7%). Critically, these rates were comparable to control groups, meaning GLP-1 receptor agonists did not appear to raise the risk of common upper-airway infections above background levels^[1].

This finding is broadly consistent with the known adverse-event profiles of individual agents. The dominant side-effect signal for drugs like semaglutide has always been gastrointestinal (nausea, vomiting, diarrhoea), not respiratory. The review confirms that common respiratory symptoms do not appear to be a class-specific concern and do not require changes to routine clinical monitoring^[1].

Rare but serious signals

The review catalogued several serious pulmonary events reported in the literature: anaphylaxis with bronchospasm (four cases), acute eosinophilic pneumonia (one case), spontaneous pneumomediastinum (one case), and acute respiratory distress syndrome (two cases, one of which was fatal). All of these were drawn from case reports, and the authors emphasise that they demonstrate temporal association, not confirmed causation. The evidence certainty for these serious events remains very low under GRADE methodology^[1].

Pharmacovigilance data flagged dyspnoea and asthma-like events as disproportionately reported signals, particularly with exenatide. The authors note that exenatide and lixisenatide are exendin-4-based (derived from a non-human peptide sequence), which gives them a higher reported hypersensitivity risk compared with the human GLP-1-analogue agents such as semaglutide and liraglutide. This distinction matters: not all GLP-1 receptor agonists carry the same immunogenic profile, and exendin-4-derived agents have a structurally different origin that may explain the disproportionate reporting^[1].

Perioperative aspiration: a separate concern

The systematic review devotes particular attention to perioperative aspiration pneumonitis. GLP-1 receptor agonists delay gastric emptying as part of their mechanism of action, a pharmacological effect shared across the GLP-1 class. A patient who has followed standard pre-surgical fasting protocols may still have food in the stomach at the time of anaesthesia induction, raising the risk of aspiration during intubation^[1].

A separate cross-sectional study (the RESIDUAL study, June 2026) examined this question directly: among 93 patients scheduled for elective surgery, 42% of those who had discontinued their weekly GLP-1 receptor agonist for at least seven days still had increased residual gastric content, compared with 24% in the control group. The difference was not statistically significant in that sample, but the authors described it as a clinically relevant signal suggesting that the standard seven-day washout may not reliably clear the stomach^[2].

The systematic review recommends extended pre-procedural fasting tailored to each agent's pharmacokinetics rather than a one-size-fits-all window. This aligns with the 2024 American Society of Anesthesiologists consensus, which suggested holding GLP-1 agonists before elective procedures, though the exact timing remains debated^[1].

What the review does not settle

The authors are explicit about what remains unknown. Prospective studies with pre-specified respiratory endpoints do not yet exist for this drug class, so all the serious pulmonary signals rest on pharmacovigilance reports and case-level evidence. Whether the dyspnoea signals in pharmacovigilance databases reflect a real pharmacological mechanism or reporting bias is unresolved. And the perioperative aspiration risk, while mechanistically plausible, has not been quantified in large controlled trials^[1].

The review also does not address newer dual or triple agonists in depth. Tirzepatide (a dual GIP/GLP-1 agonist) and retatrutide (a triple agonist still in Phase 3) share the GLP-1-mediated gastric-emptying delay, but their pulmonary safety profiles have not been separately characterised in the literature the review covered. As prescribing expands beyond semaglutide and liraglutide, respiratory monitoring data for these newer agents will need to catch up.

For readers taking or considering a GLP-1 receptor agonist, the practical takeaway is narrow but important: if you are scheduled for any procedure requiring anaesthesia, tell your surgical and anaesthesia teams that you use a GLP-1 drug, and discuss whether your fasting protocol should be adjusted. The common respiratory events the review documents (upper respiratory infections, mild symptoms) are not elevated above what control groups experience. The rare serious events are documented but not established as causal.

This review adds to a growing body of safety literature on the GLP-1 class. Readers interested in the broader adverse-event profile of semaglutide can find gastrointestinal, cardiovascular and metabolic safety data on our overview page. For how perioperative risk intersects with body contouring after weight loss, see our explainer on GLP-1 drugs and plastic surgery risks. For the latest on gastrointestinal motility concerns with the class, see our coverage of GLP-1 and severe GI motility adverse events. And for how discontinuation affects outcomes, see GLP-1 discontinuation rates and reasons.