A 58-year-old man taking semaglutide, a popular weight loss medication, followed all the standard instructions before having a stomach procedure. He stopped taking his weekly dose and fasted as directed. However, doctors found his stomach still had too much food and liquid in it, forcing them to cancel the procedure. Interestingly, the same patient had successfully completed a similar procedure before without this problem. This case suggests that people taking semaglutide might need stricter preparation—possibly a full day of only liquids—before certain medical procedures, even when following normal fasting rules.

The Quick Take

  • What they studied: Whether standard fasting instructions work well enough for people taking semaglutide before stomach procedures
  • Who participated: One 58-year-old man taking semaglutide (a GLP-1 receptor agonist medication used for weight loss) who needed an upper endoscopy, which is a procedure where doctors look inside the stomach using a small camera
  • Key finding: Even though the patient followed all standard preparation guidelines and stopped his medication, his stomach still contained too much food and liquid when he arrived for the procedure, requiring cancellation
  • What it means for you: If you take semaglutide and need a stomach procedure, talk to your doctor about possibly doing a stricter liquid-only diet for 24 hours before the procedure, rather than just following standard fasting rules. This is preliminary evidence from one case, so discuss your specific situation with your healthcare provider

The Research Details

This is a case report, which means doctors documented what happened with one specific patient. The patient was a 58-year-old man who was scheduled for an upper endoscopy—a procedure where a thin tube with a camera is inserted down the throat to examine the stomach. Before the procedure, he followed standard preparation instructions: he fasted (didn’t eat or drink) for the recommended time period and stopped taking his weekly semaglutide dose, which is a medication that slows down how quickly the stomach empties food.

The interesting part of this case is that the same patient had successfully completed a similar procedure (both upper endoscopy and colonoscopy) in the past after stopping the same medication dose, and at that time his stomach was completely empty. This time, however, when doctors looked at his stomach before starting the procedure, they found it still contained a significant amount of food and liquid, so they had to cancel the procedure.

The doctors documented this unusual situation because it raised questions about whether standard fasting guidelines are adequate for people taking semaglutide.

This case matters because semaglutide is increasingly prescribed for weight loss, and many patients taking it will eventually need medical procedures that require an empty stomach. If standard preparation instructions don’t always work for these patients, doctors need to know this so they can give better instructions. Understanding this problem helps prevent wasted appointments and keeps patients safe during procedures.

This is a single case report, which is the lowest level of scientific evidence. It describes what happened with one person, not a large group. The findings are interesting and worth noting, but they cannot prove that all people taking semaglutide will have this problem. The fact that the same patient had different results on different occasions suggests that individual factors may play a role. More research with larger groups of patients would be needed to confirm whether this is a common problem or an unusual occurrence

What the Results Show

The main finding is that a patient taking semaglutide had residual gastric contents (food and liquid remaining in the stomach) despite following standard fasting guidelines and stopping his medication dose. This was unexpected because the patient had successfully completed a similar procedure previously without any residual contents.

The procedure had to be canceled because the presence of stomach contents creates a safety risk during endoscopy. When a patient’s stomach isn’t empty during this procedure, there’s a risk of food or liquid entering the lungs, which is a serious complication.

The doctors noted that the only difference between this unsuccessful attempt and the previous successful procedure was unclear—the patient followed the same preparation instructions both times. This suggests that factors beyond standard fasting guidelines might affect how quickly semaglutide slows stomach emptying.

The case highlights that semaglutide’s effect on stomach emptying may be unpredictable in some patients. The medication works by slowing down how quickly food moves from the stomach into the small intestine, which is part of how it helps with weight loss. However, this same effect can complicate medical procedures that require an empty stomach. The variability in outcomes (successful preparation one time, unsuccessful another time) suggests that individual patient factors—such as the type of food eaten before fasting, stress levels, or other medications—might influence how much residual stomach content remains.

This case adds to growing awareness in the medical community that GLP-1 medications like semaglutide may require special consideration before procedures. Previous research has shown that these medications slow gastric emptying, but most guidelines haven’t been updated to reflect this. This case suggests that current standard fasting recommendations may have been developed before these newer weight loss medications became widely used, and the recommendations might need updating.

This is a single case report involving only one patient, so the findings cannot be generalized to all people taking semaglutide. The case doesn’t explain why the same patient had different outcomes on different occasions, which limits what we can learn from it. The report doesn’t include detailed information about the patient’s diet, stress level, or other factors that might have affected stomach emptying. Additionally, we don’t know how common this problem is—it could be rare or relatively frequent. Much larger studies would be needed to determine how often this happens and which patients are at highest risk

The Bottom Line

If you take semaglutide and need a procedure requiring an empty stomach, discuss with your doctor whether you should follow a stricter preparation plan. The evidence suggests considering a 24-hour liquid-only diet before the procedure, rather than standard fasting alone. This is a cautious recommendation based on one case, so personalized medical advice from your healthcare provider is essential. Do not change your medication schedule without explicit instructions from your doctor.

This information is most relevant for people taking semaglutide (Ozempic, Wegovy, or similar GLP-1 medications) who are scheduled for upper endoscopy or other procedures requiring an empty stomach. It’s also important for doctors and medical staff who perform these procedures. People taking other GLP-1 medications should discuss with their doctors whether similar precautions might apply to them. This case is less relevant for people not taking these medications or those taking them for diabetes rather than weight loss, though the same principle may apply.

If you follow stricter preparation guidelines (such as a 24-hour liquid diet), you should expect your stomach to be empty by the time of your procedure, typically within 6-8 hours of stopping all intake. However, individual timing varies. The key is coordinating the timing with your doctor based on your specific procedure schedule

Want to Apply This Research?

  • If you take semaglutide and have upcoming procedures, use the app to log: (1) your semaglutide dose dates and amounts, (2) any procedures scheduled, and (3) your pre-procedure preparation plan. Track what you ate and drank in the 24 hours before the procedure to identify patterns that might affect stomach emptying
  • Set reminders in the app for pre-procedure preparation, starting 24 hours before your scheduled procedure. Create a checklist: stop eating solid foods at the designated time, switch to clear liquids only, note when you stop all intake, and confirm your medication adjustments with your doctor. Share this plan with your healthcare provider
  • If you have multiple procedures while taking semaglutide, use the app to track which preparation methods were successful and which weren’t. Note any differences in how you felt, what you ate beforehand, or other factors. Share this information with your doctor to help develop the best preparation plan for future procedures

This case report describes one patient’s experience and should not be considered definitive medical guidance. If you take semaglutide or similar GLP-1 medications and need any medical procedure requiring fasting or an empty stomach, you must discuss preparation instructions with your healthcare provider. Do not modify your medication schedule or fasting plan without explicit instructions from your doctor. This information is educational and not a substitute for professional medical advice, diagnosis, or treatment. Always consult with your healthcare team about your specific situation before any procedure