GLP-1 Era Arrives in the OR

Today, approximately 1 in every 8 US adults take glucagon-like peptide-1 receptor agonist (GLP-1RA) drugs, and half of all Americans may benefit from doing so.

Many surgeons now encounter these patients in daily practice, even if their surgical specialty is not directly related to obesity.

This reality leads to important questions: How can GLP-1RA drugs help patients prepare for safer, more effective surgery? What information will surgeons need to optimize outcomes for patients taking these drugs?

An Ongoing Conversation

Although GLP-1RA drugs are highly popular and frequently prescribed, their use has been widespread for only a few years. In that time, a wide range of benefits has emerged, ranging from the expected weight loss and glycemic control to improvements in cardiovascular and kidney health, reductions in inflammation and related autoimmune disease, positive shifts in mood and anxiety disorders, and even remission of addiction symptoms. This panoply has helped drive the drugs’ popularity.

“In many ways, this is the golden era for the treatment of chronic disease,” said Thomas C. Tsai, MD, MPH, FACS, a bariatric surgeon and Medical Director for Health Policy Research in the ACS Division of Advocacy and Health Policy, at an ACS press conference in October 2025, urging wider access to and use of GLP-1RA drugs in patients with obesity.

However, perhaps by the very fact of their wide-ranging outcomes, much about GLP-1RAs remains unknown. Scientific literature on GLP-1RA drugs is rapidly accumulating, but the duration of use is insufficient to clarify the full scope of these benefits, as well as any drawbacks the drugs may pose.

Consequently, the ongoing conversation on how surgeons can best help GLP-1RA users prepare for surgery remains a priority.

“It’s important for us as physicians, and surgeons in particular, to be aware of the prevalence of their use, as well as the potential implications in terms of perioperative management, risk mitigation, and preparation for surgery,” added Vivek N. Prachand, MD, FACS, a professor of surgery at The University of Chicago in Illinois.

Preventing Gastric Content Aspiration

Ann M. Rogers, MD, FACS, the immediate past president of the American Society for Metabolic and Bariatric Surgery (ASMBS) and a professor emerita of bariatric surgery at Penn State Health in Hershey, Pennsylvania, explained the most frequent scenario in which surgeons encounter patients taking GLP-1RA drugs.

“It’s very common now for patients to be on them prior to surgery, not necessarily because it was started as a specific way to make the surgery safer, but just because they were already on it,” said Dr. Rogers.

As a result, a top concern for many surgeons, including those who are not involved in bariatric surgery, is avoiding a specific risk that may be intensified by GLP-1RA usage: gastric content aspiration.

It is rare that anesthetized patients aspirate gastric contents, and even rarer that such aspiration causes pneumonia. Nonetheless, the complication is serious enough to warrant fasting prior to most surgeries. The challenge with GLP-1RA drugs is that they depress appetite in part by slowing gastric emptying, and therefore standard fasting times may not eliminate gastric contents.

In response to these concerns, surgical societies have updated protocols aimed at mitigating the risk of aspiration. In 2023, the American Society of Anesthesiologists advised holding all GLP-1RA drugs for a day (if taken daily) or a week (if taken weekly) before surgery. In contrast, 2024 guidance from the American Gastroenterological Association suggested most patients using GLP-1RA drugs could continue them safely before surgery.¹

More recently, multisociety guidance endorsed by both organizations has advised that most patients can continue GLP-1RAs before surgery.² Data now suggest that suspending intake may sacrifice glycemic control and fail to eliminate residual gastric contents,³ but those using GLP-1RA drugs continuously do not experience elevated aspiration pneumonia risk.³

Thomas K. Varghese Jr., MD, MS, MBA, FACS, chief of general thoracic surgery at the University of Utah in Salt Lake City, offered a more cautious perspective: “It’s still too early right now, I think, for us to really know what the true incidence rate is around adverse events with GLP-1 receptor agonists.”

But per current guidelines, it appears limiting GLP-1RA intake before surgery could be unnecessary, easing concerns about balancing efficient surgery with patient safety.

Lowering Body Mass

Beyond preventing complications, many surgeons are embracing the opportunity to improve patient outcomes with GLP-1RA drugs. Because obesity plays a role in the outcomes of many surgical procedures, the most intuitive focus for many surgeons is lowering body mass index (BMI) with preoperative GLP-1RA use.

“We do a lot of abdominal wall reconstruction and foregut and esophageal procedures, many of which benefit from having patients be at a lower BMI range so that the long-term outcomes of the procedures are better in terms of reduced risk of recurrence, reduced reflux, and so forth. There are similar strategies used, for example at our institution, with transplant patients and orthopaedic patients who need to lose weight,” said Dr. Prachand, whose practice focuses on minimally invasive surgery.

The ASMBS and other organizations offer no official guidance on which patients should engage in GLP-1RA therapy before bariatric or other types of surgery, and some research has found, rather counterintuitively, that BMI and postoperative risk are not clearly associated.⁴

However, prescribing GLP-1RAs to lower BMI before surgery aligns with emerging evidence that this approach can help patients reduce weight and lower postsurgical risks.⁵ For example, a 2025 study of 70 patients undergoing elective hernia repair after GLP-1RA usage found a 30-day morbidity rate of 9.1%,⁵ a rate lower than typical.

Research results are more definitive for those patients with unusually high or low BMIs. For example, a study presented at the 2025 annual meeting of the ASMBS using ACS Metabolic and Bariatric Surgery Accreditation and Quality Improvement Program data found the overall occurrence of mortality and morbidity rose from 2.77% in those with BMIs of 30 to 34.9, to 3.99% in those with BMIs greater than 70, with a marked increase in all BMI levels greater than 50.⁶

Dr. Rogers explained how her surgical practice would use GLP-1RA drugs in response to that risk level. “If somebody came in, particularly with a BMI in the 60s or 70s, we would get a little concerned about the patient being at an increased risk for anesthetic and other complications related to the surgery. So, we might ask them to do a 5% or 10% weight reduction prior to having surgery, and that is a patient scenario where you could consider these GLP-1RA medications, which would get such a patient to where we thought it would be safer for them to have an operation.”

Nutritional Status

Lowering BMI before surgery is one kind of prehabilitation, a collection of practices meant to optimize patient health before surgery.

To help surgical teams put a range of approaches into practice, Dr. Varghese and colleagues developed Strong for Surgery with the ACS. The program offers a series of preoperative checklists designed to help surgical teams comprehensively assess prehabilitation needs and direct patients toward evidence-based practice from the first point of contact in the system. The program is now active at 340 clinical sites and three state collaboratives in the US.

“When we first started Strong for Surgery, up to 30% to 40% of malnourished patients had no interventions done prior to going for elective surgery. It was eye-opening beyond belief,” said Dr. Varghese.

Issues related to malnourishment are undoubtedly present among GLP-1RA users. A range of nutritional issues, including vitamin D, iron, and protein deficiencies and muscle loss have been established as frequent outcomes for this patient group,^8,9 thought to arise from reduced caloric intake and weight loss. However, unlike bariatric surgery, which generates the same results, no formal monitoring protocols have yet been established for GLP-1RAs.⁹

This gap in guidance includes Strong for Surgery. Its nutrition checklist currently includes the query, “Has the patient had a poor appetite—eating less than half of meals or fewer than two meals per day?” It makes no distinction between patients experiencing health problems and those using GLP-1RA drugs, a detail Dr. Varghese acknowledged is imperfect.

Formal changes to monitoring protocols are pending. “It’s got to rise to a certain level of evidence, including multiple randomized clinical trials and meta-analyses of clinical trials, before it gets incorporated into a framework like Strong for Surgery,” Dr. Varghese explained. “We’re waiting on the evidence right now.”

Nonetheless, the checklist’s general advice for “referral to registered dietitian for evaluation of malnutrition” may be appropriate for clinicians concerned about nutritional issues in GLP-1RA users preparing for surgery.

Wound Healing, Surgical Site Infections, and Other Complications

Intriguingly, some evidence suggests GLP-1RA usage may improve surgical complications, such as surgical site infections and wound healing. This may stand to reason, as improved glycemic control can reduce infections and improve healing in diabetic patients, and reducing the amount of inflammatory adipose tissue in the body could ease chronic inflammation and therefore facilitate healing. On the other hand, poor nutritional status and sarcopenia, which are commonly induced by GLP-1RA intake, may slow postoperative recovery.

Because GLP-1RA use can cause both anti-inflammatory healing benefits and adverse nutritional depletion, the association of GLP-1RA usage with surgical complications remains under investigation.

Some research has shown clear benefits to preoperative GLP-1RA use. One retrospective observational study of nearly 22,000 surgical patients with type 1 or 2 diabetes found that those taking GLP-1RA medications had significantly reduced risks of postoperative wound dehiscence (relative risk, 0.71). This cohort’s risk of postoperative hematoma also dropped by more than half (relative risk, 0.44).¹⁰

Another study of diabetic and nondiabetic GLP-1RA users compared with nonusers found that the users had a significantly lower composite wound complication rate (9.0% versus 17.1%), including reduced surgical site infections (4.1% versus 8.1%) and wound dehiscence (3.8% versus 7.8%), with much of that benefit occurring in nondiabetic patients.¹¹

A third study, a 2025 meta-analysis of more than 97,000 patients that defined a single outcome of overall complications, described existing data as heterogeneous and low in quality. But it also found that preoperative GLP-1RA usage offered an appreciable protective effect against overall surgical complications (odds ratio, 0.78 [95% CI: 0.59–1.05] relative to nonusers).¹²

However, other studies have shown no such benefits. A meta-analysis of more than 27,000 spinal surgery patients found no difference between GLP-1RA users and nonusers on surgical complications such as pseudoarthrosis, surgical site infections, and deep vein thrombosis.¹³

Another study examined data on approximately 139,000 patients who had undergone major surgery and found GLP-1RA exposure and surgical complications such as sepsis, surgical site infections, thromboembolism, and cardiopulmonary failure were not associated, including in those with recent versus more distant GLP-1RA usage.¹⁴

The combination of these findings can be framed positively: GLP-1RAs either help reduce surgical complications, or at least do nothing to increase complications.

Pursuing Guidance, Seeking Serendipity

One thing is certain: Anti-obesity medications will continue to attract many patients.

“I think the use is going to continue,” Dr. Rogers said—perhaps confounding surgical teams, but eventually, time, attention, and more data will lead to improved patient health and better surgical outcomes.

M. Sophia Newman is the Medical Writer and Speechwriter in the ACS Division of Integrated Communications in Chicago, IL.

References

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2. American Society of Anesthesiologists. Most patients can continue diabetes, weight loss GLP-1 drugs before surgery, those at highest risk for GI problems should follow liquid diet before procedure. Published October 29, 2024. https://www.asahq.org/about-asa/newsroom/news-releases/2024/10/new-multi-society-glp-1-guidance. Accessed May 13, 2026.
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