In a small case series, 80% of patients on GLP-1 receptor agonists had delayed stomach emptying, and semaglutide users showed the most widespread gut slowdown.
80%of patients on GLP-1 drugs had delayed gastric emptying measured by wireless motility capsule
What the researchers found
Using wireless motility capsule testing, researchers measured transit times throughout the entire digestive tract in 10 patients taking GLP-1 receptor agonists. Delayed gastric emptying was observed in 80% of patients (8 out of 10). Delayed whole-gut transit was seen in 44% of patients.
Notably, the 3 patients on semaglutide at 1 mg had the longest gastric emptying times, the most delayed whole-gut transit, and were the only patients who also showed delayed small bowel transit time. This suggests semaglutide may have more pronounced effects on gut motility compared to other GLP-1 drugs in this series.
Why it matters
GLP-1 drugs like semaglutide and tirzepatide are now taken by millions of people. While stomach-slowing effects are well known, this study provides some of the first data showing these drugs may affect motility throughout the entire digestive tract. Understanding this is important for managing side effects like constipation, bloating, and gastroparesis that many patients experience.
How the study worked
This was a retrospective case series at a single medical center. Researchers reviewed records of 10 patients who were taking GLP-1 receptor agonists and had undergone wireless motility capsule testing — a procedure where patients swallow a small electronic capsule that measures pressure, pH, and transit time as it passes through the stomach, small intestine, and colon.
What this study cannot tell us
This was a very small retrospective case series with only 10 patients at a single center, so the findings cannot be generalized. There was no control group for comparison. Patients were tested for existing GI complaints (constipation or gastroparesis), which may bias toward those already experiencing motility problems. Different patients were on different GLP-1 drugs at different doses, making direct drug comparisons unreliable.
How to read the evidence
This is a retrospective case series with only 10 patients and no control group, representing one of the lowest levels of clinical evidence. While the findings are suggestive, they are preliminary and cannot establish causation.
When this study was published
Published in 2025, this is very recent research using modern wireless motility capsule technology to study a timely question about GLP-1 drugs.
The bigger picture
Most GLP-1 research on gut motility has focused on the stomach. This study adds to growing evidence that these drugs affect the entire digestive system, not just gastric emptying. As GLP-1 prescriptions surge globally, understanding the full spectrum of gastrointestinal effects becomes clinically important for managing the millions of patients on these medications.
Questions still open
- Do GLP-1 drugs slow gut motility equally throughout the digestive tract, or is the effect stronger in certain regions?
- Does gut motility return to normal after stopping GLP-1 drugs, and if so, how quickly?
- Are the whole-gut motility effects dose-dependent, and does semaglutide truly cause more slowdown than other GLP-1 drugs?
Common questions
Do GLP-1 drugs only slow down the stomach?
What is a wireless motility capsule?
Read the original research
Impact of GLP-1 Receptor Agonists on Whole-Gut Gastrointestinal Motility Using Wireless Motility Capsule: A Descriptive Single-Center Case Series.
ACG case reports journal, 12(8), e01789
Citation
Cymbal, Michael; Naseem, Zehra; Hoxha, Din; Garg, Samita. (2025). Impact of GLP-1 Receptor Agonists on Whole-Gut Gastrointestinal Motility Using Wireless Motility Capsule: A Descriptive Single-Center Case Series.. ACG case reports journal, 12(8), e01789. https://doi.org/10.14309/crj.0000000000001789