Taking Zepbound, Wegovy or Saxenda before surgery: what to tell your anaesthetist

You book a knee operation, a colonoscopy, a wisdom tooth extraction. Somewhere in the pre-admission paperwork there is a box for “current medications”. And you are on Zepbound, or Wegovy, or Saxenda, or one of the new pills. Does that matter? Yes. The honest answer to “so what do I do about it” changed between 2023 and 2024. That is why you may hear two different stories from two different clinics.

Here is what the FDA labels and the anaesthesia societies actually say, in plain English. None of it is a substitute for the conversation itself. The decision to hold the drug, continue it, or move the date is not yours alone. It belongs to your anaesthetist, your surgeon, the doctor who prescribed it, and you. What this guide can do is make sure you walk into that conversation knowing what they are weighing up.

Why an empty stomach matters more on these drugs

Part of how GLP-1 medicines work is by slowing down how fast the stomach empties into the intestine. Doctors call that gastric emptying. It is the same mechanism that keeps you full for hours after a small meal. It is also the one behind the nausea a lot of people get in the first weeks. It is not really a side effect of the drug. It is part of the point of it. There is more on the mechanism on how these treatments work.

General anaesthesia and deep sedation switch off the reflexes that normally stop stomach contents coming back up and going into the lungs. The medical word for that is aspiration. It is why you are told not to eat before a procedure. The fasting rules assume a stomach that empties at a normal speed. If the stomach empties more slowly than usual, food can still be sitting there when the fast ends. The same fast would otherwise have been long enough.

That is exactly what the FDA labels describe. The Zepbound label says the drug “delays gastric emptying”. It then reports “rare postmarketing reports of pulmonary aspiration in patients receiving GLP-1 receptor agonists undergoing elective surgeries or procedures requiring general anesthesia or deep sedation who had residual gastric contents despite reported adherence to preoperative fasting recommendations”. The Wegovy, Saxenda and Foundayo labels carry the same wording. In plain English: it has been reported, rarely, in people who said they had followed the fasting instructions they were given. Two things in that sentence are doing a lot of work: rare, and despite adherence.

The advice changed in 2024 — which is why answers differ

In 2023 the American Society of Anesthesiologists put out consensus-based guidance for people on GLP-1 drugs having elective procedures. As the Military Medicine review summarises it, the 2023 position was “holding GLP-1 RA daily medications on the day of surgery and weekly medications 1 wk prior to surgery”. A 2025 review in the Journal of the Endocrine Society describes the same advice as “discontinuing GLP-1RAs one day (daily users) or one week (weekly users) before elective surgery or endoscopic esophagogastroduodenoscopy”. That last term means a camera test of the gullet, stomach and upper bowel. And that guidance is where the “skip one weekly dose” rule of thumb comes from.

It was contested almost immediately. The same review notes the 2023 guidance “did not cite studies showing an increased risk of aspiration/pneumonia in patients on GLP-1RAs undergoing elective procedures”. Meanwhile people were having procedures cancelled on the day. Others went without a drug they needed for their blood sugar. And nobody had yet measured the risk behind all of it.

So on 29 October 2024, five societies published joint guidance with a different starting position. The five were the anaesthesiologists, the gastroenterologists, the metabolic and bariatric surgeons, the society for care around surgery in people with obesity, and the gastrointestinal and endoscopic surgeons. GLP-1 therapy, the guidance says, “may be continued pre-operatively in patients without elevated-risk of delayed gastric emptying and aspiration”. Where the drug is held, the 2024 document suggests following the original ASA approach. That is the day of surgery for daily formulations, and a week before for weekly ones. It also states plainly that the right duration “is unknown”.

The Military Medicine paper records that the 2024 document was produced because of “provider uncertainty resulting from inconsistent guidance”. Its authors called it guidance rather than an evidence-based guideline, because the research does not yet exist. Two clinics can read the same material and land in different places. That is a live disagreement in the field, not one of them getting it wrong.

What puts someone in the higher-risk group

The 2024 guidance lists the things that make delayed gastric emptying more likely. One is being in the dose escalation phase, still going up in dose step by step, rather than on a steady maintenance dose. Of that phase, the guidance says it “is associated with a higher risk of delayed gastric emptying”. Dose size is another: “the higher the dose of GLP-1RA, the more likely the risk of gastrointestinal side effects”. Weekly rather than daily formulations is on the list too. So are current gut symptoms — nausea, vomiting, abdominal pain, indigestion, constipation. And so are other conditions that slow the gut anyway, “such as but not limited to bowel dysmotility, gastroparesis, and Parkinson’s disease”.

If any of that applies, the guidance points to practical options rather than automatic cancellation. One is a “preoperative liquid diet for at least 24 h, as performed in patients undergoing colonoscopy and bariatric surgery”. Another is to weigh “the benefits and risks of rapid sequence induction of general anesthesia for tracheal intubation to minimize aspiration risk versus procedure cancellation”. Rapid sequence induction means putting someone under and getting the breathing tube in quickly; the guidance asks for that to be weighed against calling the procedure off. A third option is point-of-care gastric ultrasound, where a service has it. That is a scan at the bedside, to see whether the stomach is actually empty. The guidance notes this “may be clinically limited based on institutional resources, inter-user variability, and credentialing requirements”. In plain terms: not every hospital can do it, and how reliable it is depends on who is doing the scan.

There is one more line worth knowing about, because it is unusual for a clinical document to say it out loud. The guidance looks at holding GLP-1 therapy around surgery only for patients taking it for overweight and obesity, without a clinical reason to hold it. Doing that, it warns, “could constitute overweight and obesity bias, which should be avoided”. The guidance ties the hold decision to the risk factors above rather than to why the drug was prescribed.

The pills count too

A common assumption is that this is an injection problem. It is not. The oral Wegovy pill is semaglutide, and it sits under the same FDA label with the same section 5.10 aspiration warning. Foundayo (orforglipron) is a daily tablet with no injection anywhere in it. Its label has its own “Pulmonary Aspiration During General Anesthesia or Deep Sedation” section, which states that “FOUNDAYO delays gastric emptying”. It gives the same instruction to tell healthcare providers before planned procedures.

Where daily and weekly do differ is in the hold advice. The 2023 hold periods are shorter for daily forms than for weekly ones, and the 2024 guidance still points to them. For a daily drug it is the day of surgery. For a weekly one it is a week ahead. So a daily tablet such as Foundayo, or daily Saxenda, falls under the shorter window. Weekly Zepbound or weekly Wegovy falls under the longer one. The 2024 guidance also notes that gut side effects are more common with weekly than with daily formulations.

Qsymia, Contrave, Xenical and Alli are the other medicines used for weight in the US. They are not GLP-1 drugs, and this guidance does not cover them. They still belong on your medication list. Everything you take does.

What to tell the surgical team

The FDA labels put the patient’s part in one sentence: inform healthcare providers prior to any planned surgeries or procedures. Do it early — at the point the procedure is booked, not on the morning. If the plan involves skipping a weekly dose, that only works if somebody knew a week ahead.

If you are not sure how to open that conversation, the talk to your doctor page has a question list you can take with you. And if a hold means several weeks without a dose, it is worth reading what happens when the drug leaves your system. That way it is not a surprise either.