Popular weight loss drugs like Wegovy and Ozempic could increase the risk of stomach paralysis as well as several other serious gastrointestinal conditions, according to a study published Thursday in JAMA.

This was the first large epidemiological (disease-related) study to examine these adverse effects in non-diabetic patients using the drugs specifically for weight loss, per a press release from The University of British Columbia (UBC).

The risk was linked to all semaglutides, a class of medications known as GLP-1 receptor agonists — including Ozempic (prescribed for diabetes management), Wegovy (prescribed for weight loss), Rybelsus (type 2 diabetes) and Saxenda (weight loss).


Stomach paralysis, officially known as gastroparesis, prevents the nerves and muscles in the stomach from moving food into the small intestine, which keeps digestion from occurring, as described on Cleveland Clinic’s website.

In addition to stomach paralysis, the drugs were linked to a greater risk of pancreatitis (inflammation of the pancreas) and bowel obstruction, which prevents food from passing through the small or large intestine, the release stated.

UBC researchers examined the health insurance claim records for approximately 16 million U.S. patients who were prescribed Ozempic, Wegovy or either semaglutide or liraglutide medications across a 14-year span (between 2006 and 2020).

Compared to another weight loss drug, bupropion-naltrexone, those who took a GLP-1 agonist were 3.67 times more likely to develop stomach paralysis, had a 9.09 times higher risk of pancreatitis and were 4.22 times more likely to have bowel obstruction. 


For the cases of stomach paralysis, the researchers could not assess whether the condition was temporary or permanent. 

“There are reports from other journalists where they have met patients whose symptoms have not gone away despite stopping the drugs,” study co-author Dr. Mahyar Etminan, associate professor in the Departments of Ophthalmology & Visual Sciences and Medicine at UBC, told Fox News Digital.

There are medications that can be used to help with the condition, he added.

Although these complications were rare, the researchers found them concerning, given that millions of people are using these medications worldwide.

The number of people in the U.S. using GLP-1 agonists for either diabetes or obesity reached 40 million in 2022, they noted.

“These drugs are becoming increasingly accessible, and it is concerning that, in some cases, people can simply go online and order these kinds of medications when they may not have a full understanding of what could potentially happen,” said first author Mohit Sodhi, a graduate of UBC’s experimental medicine program, in the release.

“Given the wide use of these drugs, these adverse events, although rare, must be considered by patients thinking about using them for weight loss.”

The researchers recommend that regulatory agencies and drugmakers consider updating the warning labels for their products, which currently don’t include the risk of gastroparesis. 

“This is critical information for patients to know so they can seek timely medical attention and avoid serious consequences,” said Sodhi. 

The decision about whether to take the drug in spite of these risks will depend on each patient’s individual situation, the researchers said.

“This decision should be individually assessed,” said Etminan. “There are patients where the benefit of the drugs might outweigh the risks (very obese individuals), whereas in other situations (healthy individuals who just want to lose a few pounds), the risks might outweigh the benefits.”

The study did have some limitations, the researchers noted.

“We did not have access to medical charts to ascertain all subjects’ medical histories,” said Etminan. “Also, we could not look at risk with individual GLP-1 drugs, but this is probably a class effect of these drugs.”


The researchers also did not determine whether certain groups were at higher risk of this adverse side effect, but Etminan said he suspects that those with preexisting GI conditions might be more susceptible.

California-based cardiologist Dr. Ernst von Schwarz, author of “The Secrets of Immortality,” was not involved in the study but noted that it confirmed a higher prevalence of pancreatitis, gastroparesis and bowel obstruction in patients on GLP-1 agonists. 

“On the other hand, these drugs have been shown to reduce the risk of cardiovascular events as shown for Ozempic in 2016 in diabetics and in 2023 for Wegovy,” he said in an interview with Fox News Digital.

“The achieved weight loss using GLP-1 agonists, as well as the improved glucose control, seem to have significant benefits on cardiovascular outcomes, but patients need to be informed about the relatively small incidence of abdominal side effects as seen in this cohort study,” said von Schwarz. 

“The benefits on cardiovascular risks, however, appear to outweigh the risks of side effects.”

The U.S. Food and Drug Administration (FDA) lists “ileus” as a potential side effect of Ozempic.

Ileus is the inability of the intestine (bowel) to contract normally and move waste out of the body, according to Mayo Clinic.


In August, a Louisiana woman sued Novo Nordisk, the manufacturer of Ozempic and Wegovy, and Lilly, which makes another GLP-1 agonist, Mounjaro, claiming that the companies “downplayed the severity of gastrointestinal events caused by Ozempic and Mounjaro — never, for example, warning of the risk of gastroparesis (‘paralyzed stomach’) or gastroenteritis.”

The woman, who used Ozempic for more than a year before switching to Mounjaro last month, alleged she was “severely injured as a result” of using both drugs, the suit stated. 

In a statement at the time, a spokesperson for Novo Nordisk told FOX Business that gastrointestinal events “are well-known side effects of the GLP-1 class” and “are mild to moderate in severity and of short duration.” 

The company provided the below statement to Fox News Digital on Friday, Oct. 6. 

“At Novo Nordisk, patient safety is a top priority. We work closely with the U.S. Food and Drug Administration to continuously monitor the safety profile of our medicines. The FDA-approved product labeling for Novo Nordisk’s GLP-1RA medicines indicated for use in weight management (Saxenda and Wegovy) includes information about their potential side effects, including pancreatitis, acute gallbladder disease, ileus and delayed gastric emptying.”

“Similar information is included in the product labeling for our GLP-1RA medicines indicated for the treatment of type 2 diabetes (Ozempic, Rybelsus and Victoza),” the statement went on. 

“Novo Nordisk stands behind the safety and efficacy of all of our GLP-1RA medicines when used consistent with the product labeling and approved indications.”

Novo Nordisk continued, “With respect to the study, as the authors acknowledge, the study has limitations, including potential confounding by indication and by other factors.”

The company added, “It is also important to note that the study analyzed data collected during the period between 2006 and 2020. During this time, Wegovy was not on the market; Saxenda was first approved in December 2014. In addition, Victoza was FDA-approved in January 2010 and Ozempic was FDA-approved in December 2017.”

Daniella Genovese of Fox News Digital contributed to this report.

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