As the popularity of Ozempic, Wegovy, and other GLP-1 receptor agonists skyrockets, so too do the questions surrounding their safety. Initially designed to treat type 2 diabetes, GLP-1 drugs are known to alter body composition, reducing fat mass but also affecting lean muscle. In the ICU, where patients already experience severe metabolic stress and muscle breakdown, clinicians have worried that these medications might quietly worsen outcomes.
A new study by researchers from Stanford's Department of Medicine sheds light on this concern, offering reassurance to clinicians and patients alike.
Presented at the Society of Hospital Medicine's Converge 2025 meeting, their research examines whether prior use of GLP-1 receptor agonists affects patient outcomes in the intensive care unit (ICU) - a question that had lingered without concrete data.
The findings, led by Albert Park, MD, Jason Hom, MD, and Neera Ahuja, MD, and colleagues reveal that previous use of these medications does not correlate with adverse outcomes during critical illness, alleviating fears that GLP-1 drugs, by altering body composition, could impede recovery in already vulnerable patients.
Nearly 25,000 ICU patients, rigorously matched
Using nearly a decade of data from Stanford Health Care (2015-2024), the team analyzed 24,955 adult ICU admissions. About 3% of those patients had been prescribed a GLP-1 agonist within the year prior to hospitalization.
To ensure a fair comparison, the researchers used high-dimensional propensity score matching - an advanced statistical approach that accounts for age, BMI, diabetes severity, heart failure, kidney disease, and dozens of other clinical factors. This resulted in 719 carefully matched patient pairs, essentially creating two groups that looked alike in every meaningful way except for GLP-1 use.
They then asked three straightforward but critical questions:
- Did patients die in the hospital?
- How long did they stay in the hospital?
- How long did they stay in the ICU?
Reassuring results, even in critical illness
The answer, across the board, was reassuring.
Patients with prior GLP-1 use had no higher risk of in-hospital death than those who had not taken the drugs. Their hospital stays and ICU stays were statistically indistinguishable from matched controls. Even when the team ran multiple sensitivity analyses, using different matching approaches and examining unmatched data, the core findings held.
In short: prior GLP-1 use was not associated with worse inpatient or ICU outcomes.
For clinicians making decisions around hospital admission and inpatient care, that matters. And for patients taking GLP-1 medications - many of whom worry about rare but serious complications - it offers a data-driven counterbalance to anecdote and speculation.
Why might these drugs not be harmful in the ICU?
The findings may seem surprising, given ongoing concerns about muscle loss. But the authors point to several plausible explanations. Though the study doesn't claim that GLP-1s should purposely be continued during critical illness, it does highlight that GLP-1 agonists have anti-inflammatory effects, improve insulin sensitivity, and reduce glucose variability - factors that may actually be protective during critical illness.
What comes next
The authors emphasize that more work is needed, particularly studies that directly measure muscle mass, physical function, and long-term recovery after ICU discharge. But as GLP-1 drugs continue their rapid expansion beyond diabetes care and into mainstream medicine, this study provides an important early signal of safety in one of the highest-risk clinical settings.
At a moment when public conversation about these medications is louder than ever, evidence like this helps ground the debate in solid data.
Citation
Park A, Hom J, Lorenzo J, Rao V, Hui G, Vickers M, Ahuja N. Prior GLP-1 Agonist Use Is Not Associated With Adverse Inpatient Quality Outcomes: A Propensity-Matched Analysis. Presented at SHM Converge 2025; Abstract 0007, Journal of Hospital Medicine.
