Britain’s medicines regulator intensified its crackdown on illegal weight-loss drug manufacturing, carrying out a second major enforcement operation in four months as global demand for obesity treatments fuels a surge in counterfeit and unregulated products.

On Feb. 25, Britain’s Medicines and Healthcare products Regulatory Agency (MHRA) announced raids on two locations in Lincolnshire and Nottinghamshire, seizing almost 2,000 doses of illegal weight-loss drugs and manufacturing equipment.¹

The operation follows a record seizure in October, when the agency dismantled what it described as the U.K.’s first illicit weight-loss medicine manufacturing facility.²

What was found in the most recent raid?

The most recent raid uncovered medicines labelled as containing tirzepatide and retatrutide, alongside packaging materials and commercial vehicles. Both tirzepatide and retatrutide mimic hormones that suppress appetite and regulate blood sugar.¹

According to Reuters, the crackdown underscores escalating enforcement action against illegal manufacturers exploiting surging global demand for weight-loss treatments, as regulators and pharmaceutical companies grapple with the growth of counterfeit and unregulated drugs trafficked online and through underground networks.

What was found in the raids from October?

In October, the MHRA announced what it called the world’s largest seizure of unlicensed weight-loss medicines, dismantling a factory in central England that produced jabs labelled as containing the ingredient in Mounjaro.²

The agency seized 2,000 injection pens labelled as containing tirzepatide, the active ingredient in Eli Lilly’s Mounjaro and Zepbound, as well as retatrutide, an experimental obesity drug still in trials. Tens of thousands of empty pens and raw chemicals were also confiscated.²

The MHRA said the factory was the first of its kind discovered in Britain.

“This is a victory in the fight against the shameless criminals who are putting lives at risk by peddling dangerous and illegal weight-loss jabs to make a quick buck,” health minister Wes Streeting said in a statement.

“These unregulated products, made with no regard for safety or quality, posed a major risk to unwitting customers.”

Why is there an increase in illegal weight-loss drugs?

Global pharmaceutical companies and regulators have raised alarms over the rapid spread of counterfeit and unregulated weight-loss drugs as demand surges worldwide. In Britain, the National Health Service prescribes weight-loss medicines only to patients who meet specific criteria. Those seeking private prescriptions can face costs of hundreds of pounds per month.²

In the United States, FDA Commissioner Marty Makary released a statement on X stating that the agency is expected to begin moving against copycat drugs promoted as alternatives to approved therapies, reinforcing the agency’s stance that unapproved products pose potential risks when marketed at scale.

The MHRA’s back-to-back operations signal a sustained enforcement push as authorities attempt to curb criminal networks capitalizing on one of the fastest-growing segments of the pharmaceutical market.

Sources

1. UK Drug Regulator Seizes 2,000 Doses of Illegal Weight-Loss Drugs in Latest Crackdown Reuters February 25, 2026 https://www.reuters.com/business/healthcare-pharmaceuticals/uk-drug-regulator-seizes-2000-doses-illegal-weight-loss-drugs-latest-crackdown-2026-02-25/
2. UK seizes record haul of illegal weight-loss drugs in factory raid October 24, 2025 https://www.reuters.com/sustainability/boards-policy-regulation/uk-seizes-record-haul-illegal-weight-loss-drugs-factory-raid-2025-10-24/