Weight loss drugs like Wegovy and Ozempic contain the active ingredient semaglutide, which is a GLP-1 agonist that works by slowing digestion to suppress a persons appetite. However, this process can cause problems if it slows down too much, leading to rare but severe stomach conditions in non-diabetic patients, including stomach paralysis, bowel obstruction, and pancreatitis. These conditions are not named in the warning labels for these drugs, but the labels already include warnings about certain types of bowel obstruction and pancreatitis.

The risk of these conditions is rare, but the medications widespread popularity means that tens or even hundreds of thousands of people could experience them if 1 million people are prescribed those drugs. Gastrointestinal side effects are the most common side effects reported in at least 5% of patients with these medications, including nausea, diarrhea, decreased appetite, vomiting, constipation, indigestion, and stomach pain.

It is important to note that Wegovy is the only agent of the three (Wegovy, Ozempic, and Mounjaro) approved specifically for weight loss. Although studies evaluating weight loss are available, it is not possible to fully compare study results for all three of these drugs outside of a clinical study as patient populations, doses, and study designs differ.