Counterfeit weight loss medicines worth around £2m have been seized by the Medicines and Healthcare products Regulatory Agency (MHRA) and West Midlands Police, in the latest sign that illicit GLP-1 supply is scaling up.
On Wednesday, officers raided an industrial unit in Birmingham and recovered more than 12,000 fake retatrutide and tirzepatide pens.
They also found packaging for around 30,000 further products.
Tim Duffield, Head of Intelligence at the MHRA’s Criminal Enforcement Unit, said the products have “not been assessed for safety, quality or effectiveness."
He added that there is no guarantee what they contain or whether they are contaminated.
Additionally, retatrutide is not currently authorised in the UK, so any supply outside legitimate clinical trials is illegal.
A pattern of escalating seizures
The raid follows a series of MHRA operations.
In October last year, the agency dismantled the first illicit weight loss medicine production facility found in the UK, seizing 5000 pens, thousands of empty pens and raw chemical ingredients.
In February this year, around 2000 doses were seized alongside manufacturing equipment.
Then, in May, two people were arrested after a raid on a country estate, with around 12,000 doses recovered.
How big is the problem worldwide?
The World Health Organization (WHO) has said it has seen rising reports of falsified semaglutide products in all geographic regions since 2022.
Its 2024 alert covered three falsified Ozempic batches in Brazil, the UK and the US, some of which were supplied in the regulated supply chain.
The European Medicines Agency (EMA) has also reported a sharp rise in illegal medicines sold as approved GLP-1 treatments, with semaglutide and tirzepatide among those being copied.
Europol’s Operation SHIELD VI, which ran from April to November 2025, seized €33m of counterfeit medicines and illegal supplements across 30 countries.
Europol said it exposed organised crime networks exploiting demand for weight loss drugs.
Demand is a key driver. A UCL study estimated that 1.6 million adults in England, Wales and Scotland used weight loss medications between early 2024 and early 2025.
Mounjaro’s private price tripled to more than £300 in 2025, pushing some users towards cheaper alternatives. A survey by online pharmacy MedExpress found that 21% of UK adults who had bought weight loss jabs did so from an unverified or illegal source.
What the rise in counterfeit weight loss medicines means for the pharma sector
Counterfeiting is no longer confined to the consumer end of the market.
The Birmingham seizure included packaging for tens of thousands of further units and the 2025 facility held empty pens and raw chemical ingredients.
That suggests criminal networks are sourcing components and ingredients, not just selling finished fakes.
For manufacturers, the following areas deserve attention:
- Supply chain integrity: the WHO alert shows falsified products can reach regulated channels, so serialisation, track-and-trace and verification checks matter
- Upstream controls: peptide ingredient suppliers and device and packaging vendors need rigorous qualification and auditing
- Brand protection: counterfeiters copy packaging and batch numbers, so manufacturers should monitor online and on social media channels and have takedown capability
- Enforcement partnerships: sharing intelligence and analytical data with regulators and police helps trace products to source
- Demand-side pressure: as GLP-1 demand rises, capacity constraints and pricing will keep fuelling the illicit market.
The MHRA’s #FakeMeds website offers guidance to the general public on buying medicines safely online.
