GLP-1 drugs before surgery: what changed

A September 2026 article in Advances in Surgery reviews how surgical teams should think about patients taking GLP-1 receptor agonists^[1]. It is a narrative review with suggested recommendations, not a clinical trial and not a new estimate of aspiration risk. Its practical message fits recent multi-society guidance: most patients do not automatically need to stop treatment, but risk should be assessed before anesthesia. Medication decisions belong to the prescriber and surgical team in consultation with anesthesia staff.

What the new paper actually is

Claire Rosen and Denise Gee wrote a 14-page review covering the history and mechanism of the class. They also discuss approved medicines, weight effects, bariatric-surgery context, and perioperative issues^[1]. PubMed classifies it as both a journal article and a review. The abstract says perioperative considerations are reviewed and recommendations are suggested. It describes no randomization or participant recruitment. There is no control group and no newly collected outcome.

That distinction matters because a trial readout tells readers what happened under a defined protocol. This paper interprets earlier studies and case reports alongside labels and professional guidance. The review names established GLP-1 medicines including exenatide, liraglutide, semaglutide, lixisenatide, and dulaglutide, as well as tirzepatide, which acts at both GIP and GLP-1 receptors^[1]. Of those drugs, our library currently has dedicated evidence pages for semaglutide and tirzepatide. The perioperative question is class-wide, not a tirzepatide-only finding as the empty triage tags implied.

Why anesthesia teams are paying attention

GLP-1 receptor agonists can slow gastric emptying, meaning food may leave the stomach later than expected. Under general anesthesia or deep sedation, retained stomach contents can be regurgitated and enter the lungs. That event is pulmonary aspiration. US prescribing information for tirzepatide now says aspiration has been reported during elective surgery or procedures and tells patients to inform healthcare professionals about planned procedures^[5]. A warning based on postmarketing reports establishes a safety signal, but it does not tell us how often the event occurs or prove that the medicine caused every report.

The clearest prospective measurement is a small cross-sectional study published in JAMA Surgery. It enrolled 124 fasting adults before elective procedures under anesthesia. Increased residual gastric content was found in 35 of 62 people using a once-weekly GLP-1 medicine, compared with 12 of 62 non-users. After adjustment, use was associated with a 30.5 percentage-point higher prevalence, with a 95% confidence interval from 9.9 to 51.2 percentage points^[3]. Gastric ultrasound was the endpoint. The study was not designed to count aspiration, and its small, single-center sample limits generalization.

A separate meta-analysis pooled 15 studies that measured gastric emptying rather than surgical complications. Five scintigraphy studies, totaling 247 participants, found a pooled 36-minute increase in the time for half of a solid meal to leave the stomach. Ten studies using acetaminophen absorption, a measure more reflective of liquid emptying, found no significant delay^[4]. Heterogeneity for the scintigraphy result was high at 79.4%, so the average hides meaningful differences among studies. Neither endpoint directly measures aspiration pneumonia.

What current guidance says

The 2024 multi-society document was written by representatives from anesthesia and gastroenterology organizations. Bariatric-surgery and perioperative-care groups also participated. It calls itself guidance rather than an evidence-based guideline because direct evidence is limited^[2]. Its first step is shared decision-making between the patient and all relevant care teams. The document says GLP-1 therapy may continue before a procedure when there is no elevated risk of delayed gastric emptying or aspiration.

The same guidance identifies factors that can raise concern: being in the dose-escalation phase, taking a higher dose, using a weekly formulation, having nausea or other gastrointestinal symptoms, or having another condition that slows stomach emptying^[2]. For higher-risk situations, it discusses a liquid diet before the procedure or point-of-care gastric ultrasound where trained staff and equipment are available. A team might instead change the anesthesia plan, postpone the procedure, or direct a medication hold. These are choices for a care team, not a checklist for patients to apply alone.

The guidance also says the duration of any medication hold is unknown. If a team decides that withholding is necessary, it suggests the older anesthesia-society interval as an interim approach: the day of surgery for daily formulations and one week for weekly formulations^[2]. That passage is often stripped of context online. The document places it behind an individualized risk assessment and asks clinicians to weigh aspiration concerns against disruption of metabolic care. Hyperglycemia, bridging-related hypoglycemia, and cost all enter that judgment.

What the evidence cannot answer

There is a plausible mechanism and there are case reports of aspiration. Ultrasound evidence shows more retained contents, while current labeling carries a warning. There is not yet a randomized trial showing that stopping a GLP-1 medicine for a particular number of days reduces aspiration or improves surgical outcomes. The multi-society authors explicitly say little evidence exists to identify the best perioperative approach^[2].

The available studies mix different drugs and indications. Doses, stages of treatment, procedure types, and anesthesia plans also vary. A person newly increasing weekly semaglutide who has vomiting is not the same risk profile as a symptom-free person on a stable dose. Nor should a finding about retained solids before upper endoscopy be read as an event rate for every operation. The tirzepatide safety record provides drug-specific label context, while the review addresses the broader class.

The review's authors report no financial conflicts, which helps readers assess one source of bias^[1]. It does not remove the limits of a narrative synthesis. The PubMed abstract does not describe search methods or inclusion rules, nor does it grade certainty. Guidance can support consistent conversations while the evidence develops, but it should not be mistaken for a tested protocol.

The useful takeaway before a procedure

A planned operation should prompt an early medication conversation, not an automatic last-minute cancellation or a self-directed pause. Patients should tell the surgical and anesthesia teams the exact product and formulation, plus the timing of the most recent dose. They should also say whether the dose is being increased and report any digestive symptoms. The current semaglutide evidence page and tirzepatide evidence page explain why the molecules cannot be treated as interchangeable even when perioperative guidance discusses them as a class.

Medical disclaimer: this article is for educational and journalistic purposes only and does not constitute medical advice. GLP-1 receptor agonists and tirzepatide are prescription medicines. Do not change the schedule of a prescribed medicine or restart it around surgery without instructions from the prescribing and procedural care teams. Always consult qualified healthcare professionals who know your medical history. PeptideMethods.com does not sell or distribute peptide products and does not facilitate their sale.