A quarter of GPs have treated patients who were hospitalised after using fake weight-loss jabs, concerning new research has found.
As demand for appetite-suppressing drugs such as Wegovy, Ozempic and Mounjaro continues to soar, fears are growing that counterfeit ‘black market’ medication is putting patients at risk.
More than 2.5 million Britons are thought to be using the drugs, the majority of whom pay privately as NHS access remains limited to specialised patients. The high cost of paying private – up to £300 per month – is believed to be fuelling demand.
Government officials in February this year warned that, while some of the products do contain the same active ingredient that makes them official weight-loss jabs so effective – helping users cut up to 20 per cent of their body weight – they may be produced in unsafe or unhygienic conditions and could be contaminated.
But the warnings do not seem to be putting people off, as new a survey of 267 GPs revealed a rise in exposure to the unregulated medicine in Britain.
Despite thousands of seizures of the drugs at the border, 86 per cent of GPs said they have seen an increase in patients being offered the jabs over the past year.
Nearly two-thirds said patients had experienced side effects including severe vomiting, while more than half saw patients experience diarrhoea and dehydration.
In the update earlier this year, the Medicines and Healthcare products Regulatory Agency (MHRA) said using the illegal jabs can cause serious health complications.
A quarter of general practitioners (GPs) have treated patients who were hospitalised after using fake weight-loss jabs, concerning new research has found
If the drugs are not sterile – meaning they may contain bacteria or other germs – this may trigger swelling, pain, redness and fluid leakage at the point of injection.
Infections can also lead to symptoms of fever such as fatigue, chills and sore throat.
Almost half of the GPs surveyed were concerned that patients accessing the drugs through unlicensed sources were receiving little or no medical guidance about their use.
Investigations have found unlicensed sellers in beauty salons, gyms and social media platforms. A Daily Mail investigation last November found beauticians offering them.
There has been at least one death in Britain linked to taking fake weight-loss drugs.
Ashton Collins, director of Save Face, a register of accredited practitioners for cosmetic surgery, said last year that purchasing the jabs from ‘illegal sources is like playing the lottery with your life’.
In some reports, the fake jabs have even been found on sale in fish and chip shops and pubs in London.
Some 25 per cent of the GPs raised concerns about unregulated sellers after seeing patients require hospital care following complications from the jabs.
More than 18,000 illegal and counterfeit weight-loss and diabetes medicines were seized at UK borders between January 2024 and June 2025, but it has been suggested that some jabs may bypass enforcement efforts.
Earlier this year the MHRA seized almost 2,000 doses of fake weight-loss medication just hours before they were set to be sent to customers. The drugs were busted in Nottingham and Lincolnshire.
Reports have also suggested that overseas laboratories in locations like China may be a leading imitator of the drugs loss drugs, which are sold for as little as £1.50 a vial. Dealers then buy them in bulk and sell them on for profit.
As health officials call for greater awareness around the dangers of the jabs, Asda Pharmacy has launched a scheme encouraging anyone who suspects they have purchased the fake medication to dispose of it at one of its 230 locations.
Faisal Tuddy, head of Asda Pharmacy, said: ‘We know lots of our customers are looking for help managing their weight, and it’s really important they feel confident they’re getting safe, trusted support.
‘At Asda Pharmacy, we’re here to make that journey simpler – offering friendly, professional advice and clinically appropriate options that are tailored to each individual, with support every step of the way.
‘If anyone is unsure about something they’ve bought, we’d always encourage them to pop in and have a chat with a pharmacist. Our new service is all about giving customers peace of mind – helping them feel supported, informed and able to make safer choices, without any judgement.’
Earlier this year, Dr Alison Cave, chief safety officer at MHRA, urged anyone using a suspected counterfeit 15mg Mounjaro pen carrying the batch code D873576 – and supplied by The Private Pharmacy Clinic in Birmingham – to stop using it immediately.
She continued: ‘If you have administered injections using the pen already, please be reassured that, based on the cases reviewed to date, the risk to you is low.
‘Testing has confirmed that the identified fake pens do contain tirzepatide, the active substance in Mounjaro, but because the manufacturing conditions are unknown, we cannot confirm that the contents are sterile.
‘If you suspect that you’ve had a side effect as a result of using these affected pens, or suspect it’s not a genuine product, or have a defective pen, you can report it to our MHRA Yellow Card scheme. It is important you do not try to extract any of this medicine if a pen is defective in any way.’
