GLP-1 medications before surgery or a procedure

Why the stomach matters under anesthesia

Under general anesthesia or deep sedation, the reflexes that normally protect the airway are switched down. If the stomach still holds food or liquid, some of it can travel up and be breathed into the lungs. That is pulmonary aspiration, and it is the reason people are asked to fast before a procedure.

GLP-1 medicines slow how quickly the stomach empties; the labels list this as part of how they work. The concern is that the usual fasting period may not always leave the stomach as empty as expected. The ASA notes that nausea, vomiting, indigestion or a bloated abdomen in someone taking these medicines predicts more food left in the stomach ^[13].

What each document says

In the US the warning sits in the Warnings and Precautions section under a heading about pulmonary aspiration during general anesthesia or deep sedation, and pulmonary aspiration is also listed among postmarketing reactions in section 6.2 ^[1][2]. The European product information puts it in section 4.4 and asks clinicians to consider the higher chance of residual stomach contents before such procedures ^[10].

What the labels leave open

The labels are clear about a gap in the evidence. They say the available data do not allow a recommendation on how to reduce this risk, and specifically that it is not known whether adjusting fasting instructions or pausing the medicine for a time would lower the chance of food remaining in the stomach ^[1][4].

So the label itself does not tell you to stop your medicine before surgery, and it does not tell you to keep taking it. That decision belongs to the clinicians caring for you, who can weigh the procedure, your reasons for treatment and the guidance they follow. Stopping on your own, without telling them, leaves them without the information the label wants them to have.

What anesthesia guidance has said since 2023

• American Society of Anesthesiologists, consensus-based guidance, 29 June 2023: written by its task force on preoperative fasting, which described the evidence as sparse and limited to a few case reports. For elective procedures it suggested considering holding daily GLP-1 medicines on the day of the procedure and weekly ones for a week beforehand, delaying the procedure if significant stomach symptoms are present on the day, and treating urgent cases as a full stomach. It kept the usual fasting rules, saying there was no evidence for a different fasting time ^[13].
• Multisociety clinical practice guidance, October 2024, from the American Gastroenterological Association, the American Society for Metabolic and Bariatric Surgery, the ASA, the International Society of Perioperative Care of Patients with Obesity and SAGES: perioperative use is a shared decision between the patient and the procedural, anesthesia and prescribing teams. It lists factors that raise risk: the dose-escalation phase, higher doses, weekly products, stomach symptoms and other conditions that slow the stomach. People without those factors may continue; if a hold is chosen, it points back to the 2023 ASA timings ^[14].
• The same document describes ways to reduce the risk: a liquid diet for at least 24 hours before the procedure when delayed emptying is a concern, a bedside stomach ultrasound where available, or a change in how anesthesia is started. It warns that holding the medicine can cause high blood sugar in diabetes, and that holding it only because of obesity could amount to weight bias ^[14].
• The ASA page for the 2023 guidance now notes that in October 2024 the ASA affirmed the value of the newer multisociety document ^[13]. Both are guidance for clinicians; your team may follow these or local protocols.

Who to tell, and what to tell them

• Tell the surgeon, the anesthesia team and anyone doing a procedure with sedation, including a dentist, that you take a GLP-1 medicine. The Medication Guides ask you to tell all your healthcare providers before a scheduled procedure, and MedlinePlus mentions dental surgery specifically ^[1][15].
• Say which product and dose you take, and whether it is a weekly injection or a daily tablet; the guidance treats these differently ^[13][14].
• Give the date and time of your last dose, the date your next one is due, and when you started or last increased the dose ^[14].
• Mention any nausea, vomiting, fullness, bloating or constipation in the days before, because the guidance uses these to judge risk ^[13][14].
• Tell them about insulin or a sulfonylurea too: the labels already flag low blood sugar with them, and a hold can raise blood sugar in diabetes ^[1][14].

Why the date of your last dose matters

These medicines stay in the body for a long time. The Wegovy® label gives semaglutide a half-life of about one week and estimates that, after the last maintenance-level dose, it stays in the blood for roughly five to seven weeks ^[2]. The Zepbound® label gives tirzepatide a half-life of about 5 to 6 days ^[4].

The Zepbound® and Foundayo™ labels note that the delay in stomach emptying is largest after the first dose and becomes smaller over time ^[4][6]; the EU Wegovy® document reports no clinically relevant effect on the rate of emptying with 2.4 mg, which it puts down to tolerance, while 7.2 mg has not been studied ^[10]. This is why the 2024 guidance asks about the escalation phase, and why a precise date and time is more useful to your team than “last week”.

If your care team pauses your doses

Sometimes a team decides to hold one or more doses around a procedure. Restarting afterwards follows the label of your medicine. The Wegovy® label says that after 2 or more consecutive missed weekly injections, dose escalation starts again at a lower dose to reduce stomach side effects, and its Medication Guide asks you to contact your healthcare provider about restarting ^[2]. The Foundayo™ label sets the same threshold at 7 or more consecutive daily doses ^[6].

Ask before the procedure who will tell you when and how to restart, so the plan does not get lost between the surgical team and your regular prescriber. If you have diabetes, ask who is covering your blood sugar while doses are held ^[13][14].

Ozempic®, Wegovy®, Rybelsus®, Saxenda® and Victoza® are registered trademarks of Novo Nordisk A/S. Mounjaro®, Zepbound® and Trulicity® are registered trademarks and Foundayo™ is a trademark of Eli Lilly and Company. PepLabo is not affiliated with or endorsed by Novo Nordisk or Eli Lilly and Company.

When to get help