Quick answer: For GLP-1 before surgery, the 2023 American Society of Anesthesiologists (ASA) advice was to hold a weekly GLP-1 drug (such as Ozempic, Wegovy, Mounjaro or Zepbound) for one week before elective surgery and a daily one on the day of surgery.[1] A 2024 multi-society guidance that ASA joined updated this: many people can keep taking the drug, holding it is reserved for higher-risk patients, and a 24-hour liquid diet before the procedure is suggested when there is concern.[2] Always follow your own surgical team’s instructions.
This guide explains why these drugs matter for anesthesia, what each guidance says, and how to restart. For background on the drugs, see our GLP-1 basics hub and the semaglutide and tirzepatide profiles.
Why GLP-1 drugs matter before anesthesia
GLP-1 drugs slow how fast the stomach empties. Under general anesthesia or deep sedation, the body’s protective reflexes are reduced, so food or liquid left in the stomach can come back up and be breathed into the lungs. This is called pulmonary aspiration and can cause serious pneumonia.
The Wegovy and Zepbound labels now warn that there have been rare reports of aspiration in people taking GLP-1 drugs during elective surgery or procedures, some of whom had food in the stomach even though they followed fasting instructions.[3][6] The labels add that available data are not enough to say whether changing fasting rules or stopping the drug reduces this risk, and they tell patients to inform their providers before any planned procedure.[3]
What the research found about aspiration risk
- Retained food is more common. In a 2023 study of 404 people having upper endoscopy, increased stomach contents were found in 24.2% of those who had taken semaglutide in the prior 30 days versus 5.1% of others. One aspiration occurred, in the semaglutide group. Among semaglutide users, those with retained food had paused the drug for about as long (10.5 days on average) as those without (10.2 days).[4]
- Aspiration itself appears rare. A 2025 meta-analysis of 23 studies (262,018 patients) found GLP-1 users had about 4.5 times the odds of retained stomach contents and of procedures being stopped early, but no significant difference in aspiration pneumonia.[5]
- Liquid prep helps. In the same meta-analysis, retained contents were much less likely when upper endoscopy was done on the same day as a colonoscopy, which involves a clear-liquid prep.[5]
The 2023 ASA guidance
In June 2023, the ASA’s Task Force on Preoperative Fasting suggested the following for elective procedures:[1]
| Situation | ASA 2023 suggestion |
|---|---|
| Weekly GLP-1 (Ozempic, Wegovy, Mounjaro, Zepbound) | Hold for one week before the procedure |
| Daily GLP-1 (for example, liraglutide or oral semaglutide) | Hold on the day of the procedure |
| Taking it for diabetes | Consider consulting an endocrinologist to avoid high blood sugar |
| GI symptoms on the day (severe nausea, vomiting, bloating, belly pain) | Consider delaying the procedure |
| Drug not held, no symptoms | Treat as a “full stomach” or check with gastric ultrasound |
The ASA noted at the time that there was little scientific data and called for more research.[1]
The 2024 multi-society guidance
In late 2024, five groups (the American Gastroenterological Association, American Society for Metabolic and Bariatric Surgery, American Society of Anesthesiologists, International Society of Perioperative Care of Patients with Obesity, and Society of American Gastrointestinal and Endoscopic Surgeons) published joint guidance. Its main points:[2]
- Decide together. Whether to continue should be a shared decision between you and your procedure, anesthesia and prescribing teams.
- Many people can continue. The drug may be continued in patients without elevated risk. Stopping it can cause problems of its own, such as high blood sugar.
- Higher-risk features include being in the dose-escalation phase, taking a higher dose, weekly (rather than daily) dosing, having GI symptoms such as nausea, vomiting, belly pain or constipation, and other conditions that slow the stomach (such as gastroparesis or Parkinson’s disease).
- If holding is chosen, follow the original ASA timing: the day of surgery for daily drugs, one week before for weekly drugs.
- A liquid diet for at least 24 hours before the procedure can be used when delayed emptying is a concern, as is done before colonoscopy and bariatric surgery.
- On the day, a point-of-care gastric ultrasound or anesthesia techniques that protect the airway can be used if retained food is suspected.
The guidance also warns that withholding these drugs only because someone has obesity, without a specific risk, could amount to weight bias.[2]
How to restart after surgery
Restarting is usually straightforward once you are eating and drinking normally and your surgical team agrees. The label rules on missed doses help:
- Wegovy injection: if one weekly dose is missed, it can be given if the next dose is more than 2 days away. If 2 or more weekly doses in a row are missed, the label says to restart dose escalation at a lower dose to reduce stomach side effects.[3]
- Zepbound: a missed dose can be taken within 4 days; after that, skip it and resume on the usual day.[6]
Holding a single weekly dose for surgery usually means you can resume your normal dose, but if recovery delays you longer, ask your prescriber whether to step down. Expect some return of GLP-1 nausea if you restart at a higher dose after a break. Our GLP-1 dose conversion chart and guide to traveling with GLP-1 medications also cover schedule changes.
Checklist before your procedure
- Tell every team (surgeon, anesthesiologist, endoscopist, dentist doing sedation) that you take a GLP-1 drug, the dose and the day you inject.
- Ask whether to hold your dose and whether to follow a 24-hour liquid diet.
- Report any nausea, vomiting, bloating or belly pain on the day.
- If you have diabetes, ask how to manage blood sugar while the drug is held.
This article is general information and reflects the guidance available as of October 2026. Your care team may follow newer local protocols.
