If you take a GLP-1 medication like Wegovy, Ozempic, Zepbound, or Mounjaro and you have surgery coming up, you have probably heard you need to stop it first. The advice has changed a lot in the last two years, and a lot of the old guidance is now out of date. The short answer: tell your surgery team you are on a GLP-1, and let them decide. Do not just stop on your own.
Here is why this matters, what the current expert guidance says, and what you should actually do before your procedure.
Why GLP-1 Drugs Are a Concern Under Anesthesia
GLP-1 medications slow down how fast food leaves your stomach. That is part of how they work: food sits longer, you feel full longer, and you eat less. Most of the time that is a good thing. (See our semaglutide guide for how the whole class works.)
The problem comes with anesthesia. When you are put to sleep for surgery, your normal reflexes switch off, including the reflex that keeps food and acid from coming back up. If your stomach still has food or liquid in it, that material can come up and get into your lungs. Doctors call this aspiration (stomach contents getting into the lungs). It is rare, but it can cause a serious lung infection or, in the worst cases, be life-threatening.
Normally you fast before surgery so your stomach is empty. But because GLP-1 drugs slow digestion, some patients still have food in their stomach hours after they would normally be clear, even after following the usual fasting rules. Anesthesiologists have reported finding retained food in the stomachs of patients on these drugs who fasted exactly as told.
What the Guidance Used to Say (2023)
In June 2023, the American Society of Anesthesiologists (ASA) put out its first advice on this. It was simple and cautious: hold the medication. For weekly shots, stop a week before surgery. For daily versions, skip it the day of surgery. (ASA, 2023.)
That blanket rule was easy to follow but it had downsides. Stopping a GLP-1 means blood sugar can climb (a real risk for people with diabetes), hunger comes back, and some people lose ground on their weight. For a lot of patients, holding the drug caused more harm than the small aspiration risk it was trying to prevent.
What the Guidance Says Now (2024 Multi-Society Update)
In October 2024, five major medical groups released updated, joint guidance. It was endorsed by the ASA, the American Gastroenterological Association, 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. (Multi-society clinical practice guidance, 2024.)
The big shift: it moved away from one rigid rule for everyone toward an individual, case-by-case approach. The headline is that many patients no longer have to automatically stop their GLP-1 before elective (planned, non-emergency) surgery. Instead, the decision should be made together by you and your care team, weighing your aspiration risk against the downside of pausing the drug.
Who is at higher risk?
The 2024 guidance lists things that raise the odds your stomach is still full at surgery time:
- You are still in the dose-increase phase rather than on a steady maintenance dose
- You are on a higher dose
- You take a weekly shot rather than a daily form (more on this below)
- You already have stomach symptoms like nausea, vomiting, bloating, or feeling full quickly
- You have a condition that slows digestion on its own, such as gastroparesis (a stomach that empties too slowly) or Parkinson's disease
What the care team can do instead of just stopping the drug
Rather than reflexively holding the medication, the guidance suggests other ways to lower risk:
- A liquid-only diet for 24 hours before surgery for higher-risk patients, since liquids clear the stomach faster than solid food
- A quick ultrasound of the stomach right before the procedure to check whether it is empty (called point-of-care gastric ultrasound)
- Adjusting the anesthesia plan to protect the airway if the stomach is not empty, such as using a faster technique to secure the breathing tube
If, after talking it through, the team does decide to hold the drug, the guidance says the best length of time to pause is not firmly known. As a fallback, it points back to the older approach: skip the day of surgery for daily forms, and hold about a week for weekly forms.
Weekly vs. Daily Dosing Makes a Difference
Most popular GLP-1 medications are once-weekly shots: Wegovy, Ozempic, Zepbound, and Mounjaro. Tirzepatide (Zepbound and Mounjaro) and semaglutide (Wegovy and Ozempic) all fall here. A weekly drug stays in your system for days, so a single skipped dose does not clear it quickly. That is why the old rule was to stop weekly drugs roughly a week out.
Daily versions, like oral semaglutide (Rybelsus) or daily liraglutide (Saxenda), leave the body faster. For those, skipping the dose on the day of surgery has a bigger effect. Either way, the exact plan is your medical team's call, not something to guess at.
What About Colonoscopy and Endoscopy?
The same stomach-emptying concern applies to procedures done under sedation, including upper endoscopy (a camera passed down into the stomach) and colonoscopy. For an upper endoscopy especially, a stomach that still has food in it can make the procedure harder to do and, if you are sedated, raises that same aspiration risk.
Tell the doctor doing the scope that you are on a GLP-1, just like you would tell a surgeon. Some centers may extend your clear-liquid prep, adjust sedation, or in some cases reschedule if your stomach is not clear. Follow the prep instructions they give you exactly, and ask specifically what to do about your medication. Do not assume the standard prep sheet accounts for it.
What Happens to Your Blood Sugar and Weight If You Pause
This is the trade-off that drove the 2024 update. If you stop a GLP-1, even for a week or two, a few things can happen:
- Blood sugar can rise, which matters most if you have type 2 diabetes and rely on the drug to keep it controlled
- Appetite comes back, sometimes sharply, since the medication is no longer quieting hunger signals
- You may regain a little weight during the pause, though a short hold is unlikely to undo months of progress
For most people, a brief pause around surgery is manageable and you restart afterward once you are eating normally and your team gives the go-ahead. If you are curious about the bigger picture of stopping, we cover it in detail in what happens when you stop GLP-1 medications. The key point: a planned, supervised pause for a procedure is very different from quitting the drug for good.
What You Should Actually Do Before a Procedure
- Tell every provider involved that you take a GLP-1, including the surgeon, the anesthesiologist, and your prescribing clinic. Say which drug, the dose, and when you last took it.
- Ask directly whether to hold it, and for exactly how long, and what to eat or drink in the day before.
- Follow their fasting instructions to the letter. If they tell you liquids only for 24 hours, take that seriously.
- Do not stop the medication on your own without talking to a provider, especially if you have diabetes.
- For emergency surgery, there is no time to plan a hold. Just make sure the team knows you are on a GLP-1 so they can treat your stomach as if it may be full.
If you are new to these medications and have not had the surgery conversation yet, our guide on how to talk to your doctor about GLP-1 medications is a good place to start, and what to expect at your first appointment covers the basics. It is also worth knowing the everyday side effects to expect, since slowed digestion is the same effect that creates the surgery concern.
Frequently Asked Questions
Do I really have to stop my GLP-1 before every surgery?
No. Under the 2024 multi-society guidance, many patients with low aspiration risk can keep taking their GLP-1 before elective surgery. The decision depends on your dose, your symptoms, the type of procedure, and your care team's judgment. Always let them make the call.
How long before surgery should a weekly GLP-1 be held, if my team decides to hold it?
The exact safe window is not firmly established. If a hold is chosen, the guidance suggests roughly one week for weekly drugs and skipping the day of surgery for daily ones, but your team may adjust based on your situation.
Can I keep taking it before a colonoscopy?
Ask the doctor performing the procedure. Sedation carries the same aspiration concern, so tell them you are on a GLP-1 and follow whatever prep and medication instructions they give you.
What if I forgot to mention it and surgery is tomorrow?
Call the surgical or anesthesia team right away. It is better to flag it late than not at all. They can adjust the fasting plan or the anesthesia approach to keep you safe.
The Bottom Line
The rules have loosened since 2023. You probably do not need to automatically stop your GLP-1 for every procedure, but that is a decision for your care team, not a DIY choice. Tell them you are on the medication, follow their fasting instructions exactly, and never stop a diabetes medication on your own. The aspiration risk is real but manageable when everyone knows what you are taking.
Looking for a provider who manages GLP-1 treatment, including the planning around procedures? Browse GLP-1 clinics by state or search the directory to find a clinic that can guide you before and after surgery. And talk to your own doctor about what is right for your situation.