Fake weight loss products and counterfeit medicines are a “growing problem” in the UK market as price increases have resulted in more customers seeking cheaper options online, an expert has warned.
A Freedom of Information (FOI) request obtained by Chemist4U revealed that more than 18,000 illegal and counterfeit weight loss and diabetes medications were seized at UK borders between January 2024 and June 2025.
The price of Mounjaro, one of the most popular weight-loss drugs used around the world, increased in September for UK buyers, with some industry experts warning this could lead to an increase in counterfeit products in the coming months.
“The Mounjaro price hike is likely to push many people to seek cheaper alternatives, but buying from unverified sellers online, beauty outlets or social media is extremely dangerous,” said Jason Murphy, a weight loss injection specialist and Head of Pharmacy at Chemist4U.
“Our FOI data shows that the black market for weight loss injections is already thriving in the UK. Patients must be cautious. We urge them to only use regulated pharmacies to protect their health.”
Here’s what you need to know.
What are fake weight loss products?
It appears that fake weight loss products are now flooding the UK market, with consumers seeking weight loss products online that may not actually be safe for use.
Fake products can be any unlicensed medication that has not been approved by regulators or thoroughly tested for safety and efficacy.
These products may claim miraculous weight loss cures, but their ingredients can be somewhat vague.
Or, they can claim to work as effectively as registered drugs like Mounjaro without actually doing so. There are also risks associated with doses being too high, bacteria being present, or impurities in the medication.
According to Lloyds Pharmacy, these drugs “can be dangerous and even potentially fatal.”
Chemist4U found that 2,472 unregulated weight loss and diabetes drugs had been seized by the border control between January and May of this year alone. The year prior also recorded at least 15,844 seizures across the year.
Mr Murphy added: “Counterfeit medicines are a growing problem, and the surge in smuggled weight loss injections shows how criminals are exploiting rising demand,”
“These unlicensed products are not subject to the rigorous safety checks required in the UK, which means patients have no idea what they are really injecting.
“Buying weight loss injections on the black market is like playing Russian roulette with your health. Fake pens aren’t just illegal, they could be contaminated, expired or completely ineffective.”
A spokesperson from Border Force said: “Border Force works around the clock to intercept drug supply chains and will continue working closely with our overseas counterparts to identify and prevent the new methods criminals take to smuggling illegal drugs, including unregulated weight loss products.”
How to spot fake weight loss drugs?
According to Mr Murphy, there are some tell-tale signs that weight loss medication is fake.
The best way to check is to ensure the website you’re buying products from has the legitimate credentials and to consult a doctor before taking medication.
- The online pharmacy explains that registered online pharmacies in England, Wales and Scotland are expected to display the GPhC's internet pharmacy logo on their website. Alongside the GPhC logo, the pharmacy should display its unique registration number, which can be used to verify a pharmacy's credentials.
- The Head of Pharmacy also urges people to avoid taking medication altogether without consulting a healthcare professional first. It’s essential to work with a certified prescriber who can thoroughly review a person’s medical history and provide professional guidance before prescribing treatments.
- People should also double-check their prescription details and ensure the information on injection pens matches what their healthcare provider has prescribed.
- Most importantly, if customers believe they have bought fake Mounjaro or Wegovy medicine, it’s critical that they refrain from using the medicine and report it immediately to the Medicines and Healthcare products Regulatory Agency (MHRA).
