GLP-1s and Surgery: Stopping Before, and Taking Them After
2026-11-06 · 5 min read · GLPcompare Editorial
Do not decide this yourself: tell your surgeon and anesthesiologist you take a GLP-1, as early as you can. Every FDA label says so, and none of them gives a number of days to stop. Guidance from five US medical societies says most people can continue before elective surgery, with precautions for those at higher risk. A small 2026 trial points the other way for upper endoscopy, so your team may ask you to skip a dose. This is their decision, made for your procedure.
Why it matters
These medicines slow the stomach. Food can still be there when you are put under, even after fasting as instructed, and it can reach the lungs. The American Society of Anesthesiologists describes the risk as regurgitation and aspiration into the airways and lungs during general anesthesia and deep sedation, which can cause aspiration pneumonia.
What the FDA labels say
We read all ten current manufacturer labels. Each has a warning on pulmonary aspiration during general anesthesia or deep sedation, which reports rare cases in people who had food in the stomach despite following fasting instructions. Each tells prescribers to instruct patients to tell their healthcare providers about any planned surgery or procedure.
The Zepbound label is typical on what is not known: available data are "insufficient to inform recommendations", including whether changing fasting rules or stopping the medicine for a time would reduce the risk. So a label will not give you a date to stop. Each brand's warnings are on its page.
What the medical societies say
In October 2024, the American Society of Anesthesiologists, 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 published joint guidance:
- Most people should continue their GLP-1 before elective surgery.
- Those at highest risk of stomach side effects should follow a liquid diet for 24 hours before the procedure, or other measures depending on the circumstances.
- Risk is highest when you are just starting the medicine or the dose is going up, and if you have significant stomach symptoms. Ideally the procedure is scheduled with that in mind.
- The team has other tools: adjusting the anesthesia plan and using ultrasound just before the procedure to check the stomach. In rare cases, surgery is delayed.
What the newest trial found
The OCULUS trial, published in JAMA Internal Medicine in 2026, randomized people having elective upper endoscopy under sedation to skip one dose or keep taking their medicine.
| Skipped one dose | Kept taking it | |
|---|---|---|
| People in the analysis | 32 | 28 |
| Enough food left in the stomach to matter | 3.1% | 25.0% |
It was stopped early because of that difference. Two limits matter. It enrolled 60 people, and it studied endoscopy, not surgery under general anesthesia. Among those also having a colonoscopy, who were on clear liquids the day before, nobody had the problem, so what you eat the day before may matter as much as the dose. It reported no increase in other adverse events from continuing.
This is why you may hear different advice from different teams. The evidence is still moving.
After gastric bypass or sleeve
Two randomized trials studied people at least a year after surgery who had lost less than hoped. Each enrolled 70 people, alongside a 500-calorie daily deficit.
| Trial | Medicine | Length | Weight change on it | On placebo |
|---|---|---|---|---|
| BARI-STEP (our page) | Semaglutide 2.4 mg | 68 weeks | -18.0% | +0.4% |
| BARI-OPTIMISE | Liraglutide 3 mg | 24 weeks | -8.82% | -0.54% |
BARI-STEP's authors report no new safety concerns in this group, in a trial of this size. One caution from a label: the Wegovy label notes that people with a history of bariatric surgery, which it calls a risk factor for low blood sugar, had more events of serious low blood sugar on it (2 of 87 people) than on placebo (0 of 97).
These trials do not cover the first year after surgery, and we did not find an FDA label that addresses bariatric surgery as a use.
After gallbladder removal
No FDA label lists a past gallbladder removal as a reason not to take these medicines, and we found no trial that studied people who had one.
What is known concerns gallbladder problems themselves. Every label warns about acute gallbladder disease. A 2022 review of 76 randomized trials with more than 100,000 people found GLP-1s raised the relative risk of gallbladder or bile duct disease by about 37% overall, and more than doubled it (2.29 times) in trials for weight loss, with higher risk at higher doses and longer use. Tell your prescriber about your gallbladder history, and about any pain in the upper right abdomen.
Questions
How long before surgery should you stop a GLP-1? There is no single number. Labels give none, and the 2024 guidance says most people can continue. Follow what your surgical team tells you for your procedure.
Does this apply to a colonoscopy or endoscopy? The labels' warning covers procedures under general anesthesia or deep sedation, and OCULUS studied sedated endoscopy. Tell the team when you book it.
Can I restart after surgery? Ask the team who operated. If you missed doses, each label has its own rules for restarting, and some ask you to step back down: each brand's missed-dose rule.
Can a GLP-1 replace bariatric surgery? They are different treatments, and this guide does not compare them. Ask a specialist.
This article reports what labels and studies state. It is not medical advice, and your surgical team decides what is right for your procedure.