Two deaths in Northern Ireland have been reported to the UK’s medicines regulator following suspected adverse reactions linked to popular weight-loss injections, raising renewed attention on the safety monitoring of widely used obesity and diabetes treatments.
The reports were submitted to the Medicines and Healthcare products Regulatory Agency (MHRA), the government body responsible for ensuring medicines and medical devices are safe for public use.
According to newly released data, the deaths are among more than 500 suspected adverse drug reaction reports associated with GLP-1 medications filed from Northern Ireland over the past two years.
GLP-1 drugs, commonly prescribed for weight management and type 2 diabetes are marketed under several brand names, including Wegovy, Mounjaro and Ozempic.
These medications work by mimicking a hormone that regulates appetite and blood sugar levels, helping users lose weight by reducing hunger and slowing digestion.
The MHRA emphasized that reports of suspected adverse reactions do not necessarily prove a direct causal link between the medication and the reported event.
In a statement, the regulator explained that such reports only indicate that the person filing the report suspected a connection between the drug and the reaction.
Other factors, including underlying health conditions or unrelated medical issues, could also explain the events.
The data reveals that the two deaths involved a man and a woman, one in their 40s and the other in their 60s.
One case was linked to Mounjaro, the brand name for the drug tirzepatide, while the other involved an unspecified semaglutide medication.
Semaglutide is marketed under several brands, including Wegovy, Ozempic and Rybelsus.
The information was disclosed following a Freedom of Information request regarding adverse reactions to GLP-1 medications reported in Northern Ireland during 2024 and 2025.
Of the 511 suspected adverse drug reaction reports recorded during this period, healthcare professionals submitted approximately 82 percent.
A majority of the reports 458 cases were recorded in 2025, compared with 53 in 2024, reflecting a sharp increase in reporting that mirrors the rising popularity of the medications.
Among the total reports, 242 were classified as serious and 267 as non-serious. One serious report involved a child aged nine or younger.
The MHRA gathers such safety data through its Yellow Card scheme, a national monitoring system that allows both healthcare professionals and members of the public to report suspected side effects linked to medicines and medical devices.
According to the dataset, the highest number of reports were associated with Mounjaro, which accounted for 317 suspected adverse reactions.
Wegovy followed with 135 reports, while Ozempic accounted for 12.
A single report can include multiple suspected reactions experienced by one patient.
The most commonly reported side effects were gastrointestinal disorders, appearing in 327 reports.
Other frequently recorded reactions included nervous system disorders (107), general conditions and injection-site reactions (94), skin and tissue disorders (52), and psychiatric symptoms (44).
Smaller numbers of cases involved cardiac problems, musculoskeletal issues and reproductive system disorders.
The data also recorded six suspected cases of acute pancreatitis, an inflammation of the pancreas that can cause severe abdominal pain and other complications.
Three cases were linked to Mounjaro, one to Ozempic and two to unspecified GLP-1 brands.
Earlier this year, the MHRA issued a warning highlighting the potential risk of acute pancreatitis associated with these medications.
The condition is often related to gallstones, which are known to occur as a side effect of GLP-1 treatments.
Despite these reports, the use of weight-loss injections continues to grow rapidly across the UK.
Research from University College London estimates that about 1.6 million adults in England, Scotland and Wales used GLP-1 drugs for weight loss between early 2024 and early 2025.
The MHRA reiterated that patient safety remains its top priority. The agency stated that new medicines such as GLP-1 drugs are monitored more intensively to identify potential safety issues quickly.
It also noted that as the use of these medications increases, the number of Yellow Card reports is likely to rise accordingly.
The regulator added that it does not hold information on whether the medications linked to the Northern Ireland reports were prescribed by doctors, purchased through pharmacies, or obtained through unregulated sources.
