UK Seizes Massive Fake Weight-Loss Medicines Factory, Mounjaro Risk

Britain has uncovered the world's largest seizure of unlicensed weight-loss medicines, dismantling a secret factory producing dangerous injections falsely labelled as containing ingredients from Eli Lilly’s Mounjaro and Zepbound. The Medicines and Healthcare products Regulatory Agency (MHRA) confirmed the raid on Friday, marking the first discovery of its kind in the UK.

Authorities seized 2,000 injection pens claiming to contain tirzepatide—the active ingredient in Eli Lilly’s popular weight-loss drug Mounjaro—and retatrutide, an experimental obesity treatment still under clinical trials. Tens of thousands of empty pens and raw chemicals were also confiscated from the illegal operation.

Eli Lilly praised the MHRA’s action, calling it “a direct strike against criminal networks risking lives by selling counterfeit weight-loss injections.” The pharmaceutical giant warned that individuals purchasing unregulated weight-loss medicines online or through underground sources cannot know what these drugs actually contain, putting their health in serious jeopardy.

Health Minister Wes Streeting said the seizure was “a victory in the fight against shameless criminals who are putting lives at risk by peddling dangerous and illegal weight-loss jabs.” He emphasized that these unregulated products are made with no safety checks, endangering unsuspecting buyers.

Tirzepatide and retatrutide mimic natural hormones that suppress appetite and regulate blood sugar, but both are highly controlled in the UK. The National Health Service prescribes such weight-loss medicines only to patients who meet strict medical criteria, while private treatments can cost hundreds of pounds per month.

The crackdown highlights a growing global concern over counterfeit and unregulated weight-loss medicines. In the United States, some individuals have attempted to source raw ingredients online to create DIY GLP-1-based injections like semaglutide, sold under brands like Ozempic and Wegovy, due to high costs and limited access. Experts warn these self-made weight-loss injections carry serious health risks, including contamination, incorrect dosing, and lack of medical oversight.

With this historic seizure, UK authorities have sent a strong message: buying fake or black-market weight-loss medicines is not only illegal but potentially life-threatening. Regulators continue to urge the public to avoid unlicensed products and to seek safe, approved weight-loss treatments under medical supervision.