People taking GLP-1 medications for weight loss have spoken about a range of typical side effects, but specialists say certain symptoms should prompt urgent medical advice.
GLP-1 drugs such as Ozempic and Monjaro were developed for people with type 2 diabetes to help control blood sugar, though they’re now also widely used for weight management.
Among the most frequently reported side effects are nausea, vomiting, diarrhea and constipation.
As with any medication, reactions vary from person to person, so anyone worried about how they’re feeling should speak with a healthcare professional.
That said, experts and regulators have highlighted a “rare but real” risk of acute pancreatitis, according to the UK’s Medicines and Healthcare products Regulatory Agency (MHRA). Acute pancreatitis is a serious inflammation of the pancreas.
The MHRA says that “hundreds” of UK patients taking these medicines have filed reports involving pancreatic issues.
“Data published by the Medicines and Healthcare Products Regulatory Agency (MHRA) on 29 January show that, between 2007 and October 2025, the agency had received 1296 reports of pancreatitis,” the MHRA states.
In the US, the Cleveland Clinic states: “Early clinical trials evaluating the efficacy of GLP-1 receptor agonists reported a slightly increased risk of acute pancreatitis with these medications versus placebo or conventional treatment.”
It also notes that the ‘Food and Drug Administration Adverse Event Reporting System database, have reported mixed findings on the relationship between GLP-1 receptor agonist therapy and pancreatitis.’
Because of that uncertainty, clinicians have often avoided ‘using GLP-1 receptor agonists in patients with a history of acute pancreatitis.’
At present, there is ‘no clear indication’ that medicines like Ozempic raise a person’s likelihood of developing pancreatitis.
According to MayoClinic, symptoms of acute pancreatitis may include:
Mayo Clinic also says chronic pancreatitis symptoms can include unexplained weight loss and ‘symptoms of diabetes mellitus, such as excessive thirst, hunger and urination’.
In some cases, chronic pancreatitis can follow acute pancreatitis, particularly when episodes occur repeatedly.
Mayo Clinic advises contacting a doctor if you develop ‘sudden belly pain’ or pain that doesn’t get better.
It also cautions that anyone who ‘feel pain so severe’ that they can’t sit still or find a comfortable position should seek medical help.
Because some warning signs of acute pancreatitis — including stomach pain and vomiting — can resemble common GLP-1 side effects, anyone who feels unsure about their symptoms should consult their doctor.