Stopping GLP-1s Before Surgery: ASA Aspiration Guidance

GLP-1 receptor agonists slow gastric emptying — that's part of how they produce the satiety that drives weight loss. The same mechanism also means your stomach can still contain food and liquid eight hours after your last meal, even when you've followed standard pre-procedure fasting instructions. Under general anesthesia or deep sedation, residual stomach contents can be regurgitated and aspirated into the lungs, which is one of the most serious complications in anesthesia. Because of this, the American Society of Anesthesiologists (ASA) issued formal preoperative GLP-1 hold guidance in June 2023^[1] and joined a five-society multidisciplinary update in October 2024^[2]. This article is the patient-facing version of those documents.

Why GLP-1s are an anesthesia concern at all

The standard preoperative fast — nothing by mouth (NPO) for solids for 6-8 hours and clear liquids for 2 hours — was built around the normal gastric emptying time of a healthy adult^[7]. GLP-1 receptor agonists slow that emptying substantially: published gastric emptying half-times in patients on semaglutide andtirzepatide are roughly two to four times longer than baseline. Both the Wegovy^[5] and Zepbound^[6] US prescribing information explicitly warn about delayed gastric emptying in their Section 5 Warnings and Precautions. The clinical result is that a patient who has fasted the “standard” 8 hours may still have a meaningful volume of solid food in the stomach when anesthesia is induced.

What the evidence actually shows

Three lines of evidence drove the ASA to write hold guidance:

• Case reports of intraoperative aspiration. Klein and Hobai published the index case in late 2022: a patient on semaglutide who aspirated stomach contents during anesthesia induction despite an appropriate fast^[8]. Multiple similar reports followed.
• Endoscopy retrospective. Silveira and colleagues reviewed elective upper endoscopies and found that patients on semaglutide were more likely to have retained solid gastric contents at the time of the procedure than matched controls^[4].
• Prospective ultrasound. Sherwin and colleagues performed gastric ultrasound on volunteers recently started on semaglutide and documented residual gastric solids despite standard preoperative fasting^[3].

The most comprehensive synthesis to date is the Elkin 2025 systematic review and meta-analysis in Anaesthesia^[9], which pooled 28 observational studies. Across 185,414 patients in nine studies, GLP-1 use was not associated with a significant increase in actual pulmonary aspiration (OR 1.04, 95% CI 0.87-1.25). Across 165,522 patients in eighteen studies, GLP-1 use was associated with a substantial increase in residual gastric contents at the time of the procedure despite fasting (OR 5.96, 95% CI 3.96-8.98). Skipping at least one dose before the procedure reduced the residual-contents risk (OR 0.51, 95% CI 0.33-0.81). The bottom line: aspiration is a high-consequence complication and the bar for precautionary action is low, but the absolute aspiration rate when current guidance is followed remains low.

The 2023 ASA guidance (the original version)

The June 2023 ASA consensus statement^[1] recommended:

• Daily-dose GLP-1s (oral Rybelsus, oral Foundayo) — hold the dose on the day of the procedure.
• Weekly-dose GLP-1s (Wegovy, Ozempic, Zepbound,Mounjaro) — hold the dose for one week before the procedure.
• Consider delaying the procedure if the patient experiences significant GI symptoms (nausea, vomiting, abdominal distention, dyspepsia) on the day of surgery.
• If the procedure cannot be delayed, treat the patient as “full stomach” and use either rapid sequence induction (with or without cricoid pressure, which has become more controversial in recent RSI literature and is no longer universally applied) or consider regional anesthesia where feasible.

The 2024 multi-society update (the current standard)

In October 2024, the ASA, the American Gastroenterological Association, the American Society for Metabolic and Bariatric Surgery, the International Society for the Perioperative Care of Patients with Obesity, and the Society of American Gastrointestinal and Endoscopic Surgeons jointly published an updated consensus statement^[2]. The 2024 update moved away from the bright-line “hold for one week” default of the 2023 statement toward an individualized risk assessment that weighs aspiration risk against the harms of an unplanned GLP-1 interruption (loss of glycemic control in type 2 diabetes, weight regain, and rebound nausea on restart). The 2024 update does not broadly endorse continuing the drug; holding remains an explicit option, and the decision is supposed to be made case by case.

The 2024 multidisciplinary recommendations, summarized:

• The hold-versus-continue decision is individualized based on the indication for the GLP-1, the dose and duration of therapy, the presence or absence of GI symptoms, the type of procedure, and the depth of anesthesia.
• For patients on a GLP-1 for type 2 diabetes, the harms of an unplanned hold (loss of glycemic control) are explicitly weighed against aspiration risk, and the team may decide that continuing the drug with additional precautions is the safer option for that specific patient. This is not a blanket recommendation to continue.
• For patients on a GLP-1 for weight management, holding the drug is more often the default, but is still individualized.
• The 2024 update offers the option of a liquid-only diet for at least 24 hours before the procedure (similar to bowel-prep or bariatric-prep diets) when there is concern for delayed gastric emptying based on clinical symptom review — not as a universal default for every GLP-1 patient.
• Standard NPO fasting (8 hours solids, 2 hours clear liquids) is maintained in every case, whether or not the patient is additionally on the 24-hour liquid-prep diet.
• Point-of-care gastric ultrasound by the anesthesia team, where available, can be used to assess residual gastric contents immediately before induction and inform the airway plan.
• Symptomatic patients (active nausea, vomiting, bloating, dyspepsia, or a sense of fullness) should be considered high-risk for retained gastric contents regardless of fasting status or hold timing.

A practical wrinkle for the newest oral GLP-1: Foundayo (orforglipron) has a 29-49 hour half-life, so a one-day hold per the “daily oral” rule of thumb is essentially notional — there will still be substantial drug exposure on the day of the procedure. The anesthesia team should be told the last-dose date specifically and may reasonably treat the patient as “on drug” for the purposes of aspiration precautions even if a calendar hold has been observed.

What to actually do as a patient

If you are scheduled for any surgery, colonoscopy, endoscopy, or procedure under sedation, you should:

1. Tell your surgeon AND your anesthesiologist that you take a GLP-1 — even if it's on your medication list, do not assume they read it. Specifically name the drug (Wegovy, Ozempic, Zepbound, Mounjaro, Rybelsus, Foundayo) and the dose. Do this at the pre-operative visit, not at the day of the procedure.
2. Ask whether to hold the drug and for how long. For weekly injections, the typical instruction is to skip the dose for the week containing the procedure. For daily oral GLP-1s, the typical instruction is to skip the day of the procedure. But the right answer depends on your indication and the type of procedure — the surgical/anesthesia team makes the call, not the patient.
3. Follow the 24-hour liquid diet if it is recommended. Clear liquids and protein-containing clear liquids are usually allowed up until the standard 2-hour clear-liquid NPO cutoff.
4. Report any active GI symptoms on the day of the procedure — nausea, vomiting, bloating, abdominal pain, or the feeling of food still sitting in your stomach. These are red flags for retained gastric contents and should trigger a conversation about delaying the procedure or modifying the anesthesia plan.
5. Do not stop the GLP-1 on your own if you have type 2 diabetes — the loss of glycemic control can be a bigger problem than the aspiration risk. Coordinate with your prescriber and the surgical team.

Procedures where this matters most

The aspiration risk concern is highest for procedures involving general anesthesia or deep sedation where the airway is not protected at induction. These include:

• General anesthesia for any abdominal, orthopedic, or other surgery
• Upper endoscopy (EGD) under deep sedation or general anesthesia
• Colonoscopy under deep sedation
• Bronchoscopy
• Cardiac catheterization with deep sedation
• Any procedure where the ASA airway-protection criteria are not met

Procedures done under local anesthesia only (a small skin biopsy, dental cleaning, cataract under topical) generally do not require holding a GLP-1 because the airway is preserved and spontaneous protective reflexes remain intact.

What if you forgot to mention it

If you arrive at a procedure and realize you forgot to tell anyone about your GLP-1, tell the anesthesia team immediately —before any sedation is given. They may choose to:

• Delay the procedure to a later date with proper hold timing
• Treat you as a “full stomach” patient using rapid sequence induction (cricoid pressure is no longer universally applied and is at the anesthesiologist's discretion)
• Use point-of-care gastric ultrasound to assess residual contents before deciding
• Switch to an anesthetic technique that preserves airway reflexes (regional, monitored anesthesia care without deep sedation)

The worst possible move is to stay quiet because you're embarrassed or worried about delaying the schedule. Anesthesiologists would much rather know up front and adjust their plan.

What this is NOT

The ASA guidance is not a contraindication to GLP-1 therapy. It is a perioperative management protocol — a temporary modification around a single procedure. After the procedure, you can typically restart the GLP-1 at your normal weekly schedule once you are tolerating oral intake. If you held the drug for more than two weeks (e.g., a delayed surgery or a complicated recovery), check with your prescriber about whether to restart at your previous dose or step back to the previous titration step — see our GLP-1 switching guide for the standard washout-and-restart logic, which applies the same way after a procedural pause.

Bottom line

• GLP-1s slow gastric emptying enough to put patients at higher aspiration risk under anesthesia, even after standard fasting.
• The 2023 ASA guidance was “hold weekly GLP-1s for 1 week, hold daily GLP-1s for 1 day” — simple and conservative.
• The 2024 multi-society update is more nuanced: it moved from a default hold to an individualized risk assessment based on indication, dose, GI symptoms, and procedure type, and added a 24-hour clear-liquid diet for all GLP-1 patients regardless of whether the drug is held.
• The single most important action is to tell your surgeon AND anesthesiologist about the GLP-1 at your pre-operative visit and let them make the hold decision.
• Active GI symptoms on the day of the procedure are a red flag for retained gastric contents and should be reported.
• This is a perioperative management issue, not a reason to stop GLP-1 therapy long-term.

Related research

• 17 GLP-1 side effect questions answered — every common GI side effect with the trial-data context
• GLP-1 drug interaction checker — search any medication for its interaction with your GLP-1
• How to taper off a GLP-1 safely — the discontinuation guide for permanent stops
• Switching between GLP-1 medications — restart-after-pause logic also applies after a procedural hold
• GLP-1 fatigue, hair loss, and side-effect duration — what to expect on restart after a multi-week pause

Important disclaimer. This article is educational and does not constitute medical advice. The decision to hold or continue a GLP-1 before any procedure must be made by your surgeon, anesthesiologist, and prescribing clinician together, with full knowledge of your medical history, indication for the drug, and the specific procedure being performed. Do not stop a GLP-1 without consulting your prescriber, especially if you take it for type 2 diabetes.