GLP-1 weight-loss medicines and reports of deaths: what do we really know?
Recent media reports have raised understandable concerns about the safety of GLP-1 medicines such as Mounjaro (tirzepatide) and Wegovy/Ozempic (semaglutide), with headlines suggesting that hundreds of deaths have been linked to these treatments.
The figures can sound alarming. However, it is important to understand what these reports actually mean – and what they do not mean.
What are the reported numbers?
The latest figures come from the UK Medicines and Healthcare products Regulatory Agency (MHRA) Yellow Card reporting system. This system collects reports of suspected adverse drug reactions from patients, members of the public and healthcare professionals.
Up to 7 July 2026, tirzepatide had been associated with 100,810 reported adverse reactions through the Yellow Card scheme, including 10,434 classified as serious and 98 with a fatal outcome. The total number of reports classified as having a fatal outcome was 120.
For semaglutide, there were 44,073 reported adverse reactions, including 4,892 classified as serious and 37 with a fatal outcome. The total number of reports classified as having a fatal outcome was 59.
These numbers should not be interpreted as meaning that these medicines caused 120 or 59 deaths.
A Yellow Card report does not prove that the medicine caused the event
This is probably the most important point.
A Yellow Card report means that someone has suspected that a medicine may have contributed to an adverse event. It does not establish that the medicine caused it.
As the MHRA explains:
“Reports of a suspected adverse reaction do not necessarily mean that the medicine caused the event.”
A person taking a GLP-1 medicine may unfortunately become seriously ill or die for many different reasons. They may already have conditions such as obesity, diabetes, high blood pressure, cardiovascular disease or kidney disease, all of which can increase the risk of serious illness.
Professor Naveed Sattar, professor of cardiometabolic medicine at the University of Glasgow, highlighted this important issue:
“The people prescribed these medicines often already have conditions such as obesity, diabetes, high blood pressure, heart disease, and kidney disease. These conditions themselves increase the risk of serious illness and premature death.
“As a result, when millions of individuals at higher risk take a medicine, some will inevitably experience major health events or die when on treatment, regardless of whether the medicine played any role.”
In other words, a death occurring while someone is taking a medicine is not necessarily a death caused by that medicine.
Why are there so many reports?
There are now millions of people using GLP-1 medicines in the UK.
The more widely a medicine is prescribed, the more adverse events will inevitably occur among people taking it—even when those events are unrelated to the medicine.
There is also an important limitation of spontaneous reporting systems such as Yellow Card: a single person can submit multiple reports, so the number of reports does not equal the number of individual patients.
Reporting can also increase when public awareness of a potential side effect increases.
The MHRA therefore emphasises:
“We want to reassure patients that GLP-1 medicines are safe for the majority of users. It is important to place these reports in the context of the millions of GLP-1 prescriptions issued in the UK. Reporting volumes can be influenced by increased use, greater awareness of a potential adverse reaction, and other factors.”
Does this mean there are no serious risks?
No. GLP-1 medicines are not risk-free, and it is important to take potential adverse effects seriously. Gastrointestinal symptoms are among the most frequently reported side effects, including nausea, vomiting, diarrhoea,
The bottom line
GLP-1 medicines are powerful medicines, not risk-free medicines, and reports of serious adverse events—including pancreatitis—should always be taken seriously. They also need to be prescribed thoughtfully, with appropriate assessment, monitoring and clear advice about warning symptoms.
However, the recent headlines can give a misleading impression of the evidence. A Yellow Card report is a report of a suspected reaction, not proof that the medicine caused the event, and the numbers cannot be used to calculate an individual’s risk of dying from treatment.
For most people who are appropriately assessed and prescribed a GLP-1 medicine, the available evidence remains reassuring. Large randomised clinical trials have not shown an increased overall risk of death, and GLP-1 medicines have demonstrated important benefits for many people living with obesity, diabetes and cardiovascular risk.
The MHRA’s current position is clear:
“On the basis of the current evidence, the benefits of GLP-1 receptor agonists outweigh the potential risks when used in line with their authorised uses.”
The sensible approach is therefore neither to dismiss the risks nor to be frightened by alarming headlines. Good prescribing means carefully weighing the potential benefits and risks for each individual, using the best available evidence. These medicines should be used as part of a carefully considered, individualised treatment plan, with patients understanding both the potential benefits and risks and knowing when to seek medical advice.
Good prescribing is about weighing the risks and benefits for the individual – not simply asking whether a medicine has risks, but whether its potential benefits outweigh those risks for that particular person.
Sources and further reading
- Wise J. GLP-1 deaths: Are weight loss drugs linked to hundreds of fatalities? BMJ. 2026;394:e100557. doi:10.1136/bmj-2026-100557. Published 12 August 2026.
- Koronka P. More than 100 deaths after Mounjaro or Wegovy use reported. The Times. 5 August 2026.
- Whittaker R. More than 150 deaths reported after weight loss drug use. The Independent. 6 August 2026.
- Sky News. Hundreds of deaths suspected of being linked to weight-loss jabs reported to regulator. 6 August 2026.
About the author
Dr Ulrike Naumann
Dr Ulrike Naumann runs our Weight Loss Clinic and is committed to providing holistic, individualised care to help you develop healthier habits, including an improved relationship with food and exercise. She has over three decades of experience in General Practice with a special interest in obesity.
This post has been written or personally reviewed by Dr Naumann.
