MHRA Yellow Card Data: 216 Suspected Deaths Reported for GLP-1 Medicines
TL;DR: MHRA's Yellow Card scheme logged 216 suspected-link deaths for Mounjaro, Wegovy & Saxenda by 6 Aug 2026 — reports, not proven causation.
What Did the MHRA's Yellow Card Scheme Report About GLP-1 Medicines?
Coverage published on 6 August 2026 reported that the MHRA's Yellow Card scheme — the UK's system for collecting suspected adverse drug reaction reports — has recorded 216 suspected-link death reports across three licensed GLP-1-based medicines: tirzepatide (Mounjaro), semaglutide (Wegovy) and liraglutide (Saxenda).[1]
The breakdown by drug: 120 fatal reports among 106,309 total adverse-reaction reports for tirzepatide (11,554 classed as serious); 59 fatal reports among 48,148 total reports for semaglutide (5,682 serious); and 37 fatal reports among 4,528 total reports for liraglutide (1,119 serious).[1] These are cumulative counts since each medicine entered wider UK use, not a single-year total.
Velox Peptides supplies tirzepatide and retatrutide as HPLC-verified (≥99% purity) lyophilised reagents for in vitro research use only — entirely separate from the licensed medicines these figures describe. Read the tirzepatide research overview →
How Does the Yellow Card Scheme Work, and What Does a "Report" Actually Mean?
The Yellow Card scheme is a spontaneous reporting system: anyone — patients, carers, healthcare professionals, or the manufacturer itself — can submit a report if they suspect a medicine may be linked to a side effect or death. The MHRA has been explicit about what this does and does not establish: a report reflects a reporter's suspicion of a possible connection, not a confirmed causal finding. Underlying or concurrent illness may be responsible, the event could be coincidental, and the same case can be filed more than once by different reporters, so report counts should not be read as a confirmed fatality tally.[1]
This design makes Yellow Card data valuable as an early-warning signal-detection tool — it can flag patterns worth formal investigation — but weak as a stand-alone measure of a drug's actual risk, because it has no controlled comparison group and no reliable denominator of how many people were exposed.
What Is the Yellow Card Biobank, and Why Is It Investigating Pancreatitis?
What it is: A joint MHRA–Genomics England project collecting genetic samples from people who have experienced acute pancreatitis while taking a GLP-1 medicine, to test whether genetic variation explains why a minority of patients develop this reaction.
Background: On 29 January 2026 the MHRA updated GLP-1 product information and issued a safety alert confirming acute pancreatitis as a known, infrequent, but potentially fatal side effect of the drug class.[2]
Scale so far: For liraglutide alone, 137 acute and chronic pancreatitis reports were logged via Yellow Card between 2020 and 2026, one with a fatal outcome.[1]
The Biobank approach reflects how the MHRA is trying to move beyond raw report counts toward a mechanistic explanation — identifying who is more susceptible, rather than simply tallying how many reports have been filed.
How Do 216 Reports Compare With How Many People in the UK Use These Drugs?
GLP-1 medicines are now among the most widely used prescription drugs in the UK. Independent analyses put ongoing use at roughly 1.5 to 2 million-plus UK adults in the year to mid-2025, the large majority paying privately rather than accessing these medicines through the NHS.[3] Tirzepatide (Mounjaro) alone accounts for the majority of that private market.
| Medicine | Total adverse-reaction reports | Serious | Fatal (suspected link) |
|---|---|---|---|
| Tirzepatide (Mounjaro) | 106,309 | 11,554 | 120 |
| Semaglutide (Wegovy) | 48,148 | 5,682 | 59 |
| Liraglutide (Saxenda) | 4,528 | 1,119 | 37 |
Cumulative Yellow Card totals as reported 6 Aug 2026. Not a confirmed fatality count — see caveats above.
The MHRA does not publish a formal "reporting rate" from Yellow Card data because the scheme lacks a reliable prescribing denominator — it cannot say what fraction of the millions of people who have used these drugs generated a report. That absence of a denominator is exactly why raw report totals, on their own, are not a substitute for controlled pharmacovigilance studies.
What Has the MHRA Said, and What Happens Next?
Regulator's position. The MHRA has stated it wants to reassure patients that GLP-1 medicines are safe for the majority of users, while continuing to monitor the class closely through Yellow Card surveillance and the ongoing Biobank genetic study into pancreatitis risk. No product has been withdrawn or had its licence changed as a result of this reporting.[1]
This is consistent with how the MHRA has previously handled GLP-1 signal detection — updating product information and safety communications (as it did in January 2026 for pancreatitis) rather than treating raw Yellow Card totals as conclusive evidence of a new risk requiring licence action.
Does This Affect Retatrutide's Regulatory Position or UK Research-Reagent Supply?
No. This report concerns licensed pharmaceutical products — Mounjaro, Wegovy and Saxenda — prescribed to patients under MHRA marketing authorisations. Retatrutide is not yet MHRA- or FDA-approved and has no UK marketing authorisation, so it falls entirely outside this dataset. For separate MHRA context on a related licensed product, see our guide on oral semaglutide's MHRA status, and for the UK legal framework governing research reagents generally, see are research peptides legal in the UK?
Tirzepatide and retatrutide are supplied by Velox Peptides as research reagents only. They are not medicines and have not been evaluated by the MHRA or FDA. Not for human or veterinary use. See our Research Use Policy and MHRA Statement.
References
- Health Tech World. More Than 200 Deaths Suspected of Being Linked to Weight-Loss Jabs Reported to MHRA. 6 August 2026. htworld.co.uk
- MHRA. Yellow Card Biobank: GLP-1 Medicines and Pancreatitis. Genomics England / MHRA joint programme. yellowcard.mhra.gov.uk
- heySlim. Weight Loss Medication UK Statistics 2026. heyslim.co.uk
- MHRA. Yellow Card Scheme — report a suspected side effect. yellowcard.mhra.gov.uk
- Velox Peptides. See our oral semaglutide MHRA status guide for related UK regulatory context on licensed GLP-1 pharmaceuticals.
Frequently Asked Questions
What did the MHRA's Yellow Card scheme report about GLP-1 medicines?
As of reporting on 6 August 2026, the MHRA's Yellow Card scheme had logged 216 suspected-link death reports across three licensed GLP-1 medicines: 120 for tirzepatide (Mounjaro), 59 for semaglutide (Wegovy) and 37 for liraglutide (Saxenda), alongside roughly 159,000 total adverse-reaction reports for the three drugs combined.
Does a Yellow Card report prove a medicine caused a death?
No. The MHRA states explicitly that a Yellow Card report reflects a reporter's suspicion of a possible link, not a confirmed causal finding. Underlying illness, other medicines, or coincidence may explain the event, and the same case can be reported more than once by different people, so report counts are not equivalent to confirmed fatality counts.
What is the Yellow Card Biobank and why is it studying pancreatitis?
The Yellow Card Biobank is a joint MHRA and Genomics England project examining whether genetic factors influence a person's risk of acute pancreatitis while taking GLP-1 medicines. It follows a 29 January 2026 MHRA safety update confirming pancreatitis as a known, infrequent, but potentially fatal side effect of this drug class, and reports of 137 pancreatitis cases linked to liraglutide alone between 2020 and 2026.
How do 216 reports compare with how many people in the UK use these drugs?
GLP-1 medicines are among the most widely used drugs in the UK, with estimates of more than 1.5 to 2 million adults using one in the year to mid-2025, the large majority paying privately rather than via the NHS. The MHRA does not publish a formal reporting rate from Yellow Card data because the scheme lacks a reliable prescribing denominator, but the scale of use is the necessary context for interpreting cumulative report totals.
Does this MHRA report affect retatrutide or Velox Peptides' research-reagent supply?
No. The Yellow Card figures concern licensed pharmaceutical products (Mounjaro, Wegovy, Saxenda) prescribed to patients under MHRA marketing authorisations. Retatrutide is not yet MHRA-approved, and Velox Peptides supplies tirzepatide and retatrutide exclusively as in vitro research reagents, entirely separate from the licensed medicines named in this report. Read the retatrutide research overview →