# Adverse reactions to weight loss medications > Live situation record from CLSTR: https://clstr.news/situations/adverse-reactions-to-weight-loss-medications > Updated: 2026-08-11T17:30:37.000Z. Sources: 4. Developments: 2. The UK Medicines and Healthcare products Regulatory Agency (MHRA) has reported significant adverse reactions associated with weight-loss medications including Mounjaro (tirzepatide), Wegovy (semaglutide), and Saxenda (liraglutide). Data from the Yellow Card reporting system indicated over 200 deaths, with 120 linked to Mounjaro, 59 to Wegovy, and 37 to Saxenda. The agency also recorded approximately 15,000 serious adverse reactions and nearly 158,000 non-serious reactions. Authorities noted that a direct causal link between the medications and the reported deaths has not been demonstrated, suggesting pre-existing conditions may have contributed to some fatalities. As reports emerged, specific concerns were raised regarding severe side effects such as life-threatening pancreatitis. In the United States, the death of a 19-year-old student in London following the use of Tirzepatide was highlighted, with investigations suggesting a heart arrhythmia caused by nausea and vomiting. While medical professionals emphasize the benefits of these medications for obesity and diabetes, they continue to call for rigorous monitoring to characterize both known and unknown risks. ## Timeline ### 2026-08-11: Weight-loss injections linked to reports of severe side effects and deaths Reports of severe side effects and deaths linked to weight-loss drugs like Tirzepatide are rising, with 150,000 reports in the UK and a high-profile fatality of a US student in London. 2 sources. https://clstr.news/cluster/weight-loss-injections-linked-to-reports-of-severe-side-effects-and-deaths ### 2026-08-09: MHRA reports over 200 deaths linked to weight loss injections The UK's MHRA reported over 200 deaths and 15,000 serious adverse reactions linked to weight loss drugs Mounjaro, Wegovy, and Saxenda, though no direct causal link has been proven. 2 sources. https://clstr.news/cluster/mhra-reports-over-200-deaths-linked-to-weight-loss-injections --- Cite as: Adverse reactions to weight loss medications. CLSTR, https://clstr.news/situations/adverse-reactions-to-weight-loss-medications