Guidelines already say to pause GLP-1 drugs before a scope goes down the throat. The open question was how long. A retrospective study of 16,067 endoscopies, published July 9 in Surgical Endoscopy ↗, puts a number on it. Two weeks off the drug brought the risk of leftover stomach contents back down to about what it is in people who never took one.
GLP-1 receptor agonists, the class that includes semaglutide ↗ and the dual GLP-1/GIP drug tirzepatide ↗, slow how fast the stomach empties. That is part of how they blunt appetite. It is also a problem before an upper endoscopy, where a scope is passed into a sedated patient's stomach. Food or fluid left behind can be inhaled into the lungs. To avoid that, anesthesiologists want the stomach empty, and the standard workaround has been to hold the drug for some window before the procedure. Nobody agreed on the window.
The team looked at elective esophagogastroduodenoscopies, the formal name for an upper scope, done at one center between August 2023 and May 2025. They sorted patients three ways: never on a GLP-1 drug, still taking one at the time of the scope, or off it for two weeks. Then they counted retained gastric contents, defined as any solid residue or more than 100 milliliters of fluid seen during the exam.
The gap was stark. Retained contents showed up in 0.4 percent of people not on the drug, 63 out of 15,902. Among those who kept taking it, the rate was 5.83 percent, six of 103. That works out to roughly ten times the odds (OR 10.68). Patients who stopped for two weeks landed at 1.61 percent, one of 62, a level the statistics could not tell apart from the never-users (OR 2.99, with a confidence interval so wide it crosses no-effect).
So a two-week hold works. Mostly.
The exception is the one the headline math hides. Obesity, defined here as a body mass index of 28 or higher, raised the risk on its own, and it did not wash out with the hold. Obese patients who stopped their GLP-1 drug for two weeks still had about ten times the odds of a full stomach compared with never-users. For the patients most likely to be on these drugs in the first place, two weeks may not be enough.
One more wrinkle cut the other way. Patients who had a colonoscopy at the same visit, which requires a bowel cleanout beforehand, were strongly protected. Not a single retained-contents event occurred in anyone who both held the drug for two weeks and had a concurrent colonoscopy. The prep does some of the work the hold is supposed to do.
The study is retrospective and single-center, and the arms that matter are small: 103 continued users and 62 who held. One extra event in the tiny hold group would move the numbers. It cannot settle the guideline debate on its own. But it lines up with a growing pile of endoscopy data saying the same thing in different registries. The drugs really do leave food behind, the effect is large in relative terms and small in absolute terms, and simple perioperative steps blunt it.
For a general reader the practical version is short. If you take a GLP-1 drug and have an upper endoscopy coming, your care team will probably ask you to stop it for a couple of weeks, and that is well founded. If you carry more weight, expect them to be more cautious anyway, because the drug is not the only thing slowing your stomach down.