Gastric emptying

How does the stomach empty?

Gastric emptying is the process by which the stomach mixes food and liquid with digestive juices, then slowly releases the resulting mixture, called chyme, into the small intestine [1]. Doctors can measure how fast this happens with a gastric emptying scan, in which a patient eats a bland meal containing a small amount of radioactive material and is scanned for about 4 hours, or with a breath test [2]. A related disorder is gastroparesis.

How do GLP-1 medications affect gastric emptying?

Both semaglutide and tirzepatide delay gastric emptying; for tirzepatide, the delay is largest after the first dose and lessens over time [3][4]. Because emptying is slower, the Wegovy label warns the drug can affect how well other oral medications are absorbed, and the Zepbound label notes the same kind of delay may reduce the effectiveness of oral hormonal contraceptives [3][4]. Both labels also describe rare postmarketing reports of pulmonary aspiration during surgery or procedures requiring general anesthesia or deep sedation, in patients with residual stomach contents despite reported adherence to preoperative fasting recommendations; the labels say available data are insufficient to inform recommendations to mitigate this risk [3][4].