The short answer: most people do not need to stop. In October 2024, five medical societies issued joint guidance stating that most patients can safely continue GLP-1 receptor agonists as prescribed before elective surgery and endoscopy. Patients with specific risk factors for a slow-emptying stomach should follow a clear liquid diet for at least 24 hours beforehand instead. This reversed the more cautious 2023 advice to hold weekly drugs for a full week. Your anesthesiologist makes the final call, so tell them about the drug before the day of the procedure.
Why did anyone worry about this?
GLP-1 receptor agonists slow gastric emptying. That is not a side effect to be engineered away; it is part of how the drugs work, and it is a large part of why they reduce appetite.
Anesthesia depends on the opposite assumption. Standard fasting rules exist because general anesthesia suppresses the reflexes that keep stomach contents out of the airway. If the stomach still holds food after the usual fasting window, aspiration becomes possible. Case reports of retained gastric contents in patients on GLP-1s, some found during endoscopy, drove the initial alarm.
The question was never whether GLP-1s slow the stomach. It was how much that matters in practice, and what to do about it.
What the 2023 guidance said
In June 2023, the American Society of Anesthesiologists issued consensus-based guidance recommending that patients hold daily GLP-1s on the day of the procedure and weekly GLP-1s for one week before an elective procedure (ASA, June 2023).
It was explicitly consensus-based, meaning expert opinion rather than trial data. It was also easy to follow, which is why it spread quickly and why many people still hear it today.
The problem was the collateral damage. Holding a weekly drug for a week means missing a dose, and for someone taking it for type 2 diabetes that can mean losing glycemic control right before surgery. For someone in the escalation phase, it can mean restarting titration and repeating the worst of the nausea. And procedures get delayed and rescheduled constantly, so a single "hold" often turned into several missed weeks.
What the 2024 guidance changed
On October 29, 2024, five societies, the American Gastroenterological Association, the American Society of Anesthesiologists, the American Society for Metabolic and Bariatric Surgery, the International Society of Perioperative Care of Patients with Obesity, and the Society of American Gastrointestinal and Endoscopic Surgeons, published joint clinical practice guidance in Clinical Gastroenterology and Hepatology (AGA summary).
The headline conclusion: most patients may continue to safely take GLP-1 receptor agonists as prescribed before elective procedures. Patients at elevated risk for gastrointestinal side effects should follow a liquid diet for 24 hours before the procedure, and the anesthesia plan should be adjusted accordingly (ASA, October 2024).
The reasoning behind the shift was that withholding the drug carries its own risk, and that delayed gastric emptying tends to diminish over time on a stable dose rather than persisting indefinitely. Blanket rules ignored both facts.
Which risk factors actually change the plan?
This is the part worth knowing before your pre-op call, because it determines which instructions you get. The guidance identifies these as increasing aspiration risk:
- Being in the dose-escalation phase rather than on a stable maintenance dose
- Long-acting weekly agents rather than short-acting daily ones
- Higher doses
- Active GI symptoms of delayed emptying: nausea, vomiting, abdominal discomfort, feeling full long after eating
- Other conditions that slow gastric emptying independent of the drug, such as long-standing diabetes with autonomic neuropathy or Parkinson disease
If none of those apply, the expected instruction is to continue the drug and follow normal fasting rules. If some apply, expect a clear liquid diet for at least 24 hours, and possibly a point-of-care gastric ultrasound on the day to check whether the stomach is empty, or a modified anesthetic technique such as rapid sequence induction.
Note what none of those options are: stopping the drug for a month, or cancelling the procedure. Cancellation is reserved for rare cases.
What you should actually do
- Disclose the drug early. At scheduling, not on the morning of. Name it specifically, semaglutide, tirzepatide, liraglutide, dulaglutide, along with the dose and the day of the week you inject.
- Say where you are in titration. "I moved up to 1 mg three weeks ago" changes the assessment. "I have been on the same dose for eight months" changes it the other way.
- Report GI symptoms honestly. Ongoing nausea or the sense that food sits in your stomach is exactly what the risk assessment is looking for.
- Ask for the instruction in writing. Continue or hold, and if a liquid diet is required, when it starts.
- Do not self-manage. Skipping doses on your own before a procedure without telling anyone means the team plans around a drug level you no longer have, and your blood sugar may drift.
What about endoscopy and colonoscopy?
The same guidance applies, and it was written with gastroenterology societies for exactly that reason. Retained gastric contents are a particular nuisance for upper endoscopy because they obscure the view, which can mean an aborted and repeated procedure.
For colonoscopy, the bowel preparation itself is a large liquid-diet protocol, but the timing instructions may still be adjusted. Tell the unit when you book. Our companion site covers what to expect at colonoscopy.md.
What this guidance does not mean
It does not mean delayed gastric emptying is imaginary. It is real, measurable, and the reason the risk-factor list exists.
It does not mean every institution follows the 2024 update. Guidance is not a mandate, and some hospitals still use the 2023 hold protocol. If yours does, that is their call to make, and arguing with the anesthesiologist on the morning of surgery is not a winning strategy. Raise it at the pre-op visit instead.
It also does not cover emergency surgery, where there is no elective planning window and the team simply treats every stomach as full.
The bottom line
Current joint guidance from five societies says most people on a GLP-1 can keep taking it before an elective procedure. Risk is managed by diet and anesthetic technique rather than by stopping the drug, and the specific risk factors are the escalation phase, high doses, weekly agents, active GI symptoms, and other causes of slow emptying. Tell your team early, ask for written instructions, and do not improvise.
If you are weighing side effects more broadly, see our guides to GLP-1 side effects, how the drugs compare, and what happens when you stop.
Last updated: August 2026. This article is for informational purposes only and does not constitute medical advice. Do not start, stop, or change a prescription medication without talking to your prescriber.