Officials Investigate Potentially Deadly Side Effect of Weight-Loss Drugs

Health officials in the UK are launching an investigation into weight loss drugs after hundreds of consumers reported pancreas issues. Many cases of pancreatitis are linked to GLP-1, glucagon-like peptide-1 receptor agonists — and many of those cases have been fatal.

Nearly 400 reports of pancreatitis are from patients using Mounjaro, Wegovy, Ozempic and liraglutide. A quarter of these cases were reported this year alone.

The Medicines and Healthcare products Regulatory Agency’s (MHRA) Yellow Card scheme monitors adverse reactions to medical devices and medications in the UK.

“Alongside increased usage, we are seeing an upturn in the number of Yellow Card reports mentioning GLP-1 medicines and acute pancreatitis," said an MHRA spokesperson. "Sometimes genes can influence the side-effects an individual experiences when taking a medicine, so in the context of the increasing usage of these medicines and the reports of acute pancreatitis we have received, we are exploring this further.”

Acute pancreatitis leads to sudden inflammation of the gland responsible for digestion, and can often require hospitalization. Symptoms include nausea, fever, and severe abdominal pain.

A spokesperson for Lilly, the maker of Mounjaro, told The Guardian that "Patient safety is Lilly’s top priority.

“We take reports regarding patient safety seriously and actively monitor, evaluate and report safety information for all our medicines. Adverse events should be reported under the MHRA’s Yellow Card scheme, but may be caused by other factors, including pre-existing conditions.

“The Mounjaro (tirzepatide) patient information leaflet warns that inflamed pancreas (acute pancreatitis) is an uncommon side-effect (which may affect up to 1 in 100 people). It also advises patients to talk to their doctor or other healthcare professional before using Mounjaro if they have ever had pancreatitis.”

Adverse reactions to medications account for 1 in 6 hospital admissions.

Millions of people worldwide have turned to GLP-1 medications to aid in weight loss. In the U.S., that number is nearly 6% of the population, or 15 million people. The Food and Drug Administration first approved GLP-1 drugs to treat type 2 diabetes in 2005. Between 2019 and 2023, there was a 700% increase in Americans who don't have diabetes using GLP-1 medications.