More than one in five people have bought unverified weight loss jabs

A ‘critical health warning’ has been issued by online pharmacy MedExpress, after new data found that 21% of UK adults who had purchased weight loss jabs had done this from an unverified or illegal source.

A further 31% had considered buying unverified jabs and nearly half of these ‘high-risk users’ had encountered offers for illegal weight loss drugs on social media: 49.8% on TikTok, 47.9% on Instagram, and 49% on Facebook.

Adults aged 25-34 were twice as likely as the next oldest group (45-54) to purchase unverified weight loss drugs and young adults were also more likely to consider buying from unverified sources, which have not been approved by a regulatory body.

Two thousand UK adults over the age of 18 who are using or have previously used GLP-1s responded to the survey, which was conducted in November 2025. Research was conducted by MedExpress, using Attest as the survey provider.

Dr Sophie Dix, head of medical affairs at MedExpress, referred to this as a ‘crisis of counterfeit weight loss jabs’.

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She said: ‘Our survey confirms that a huge number of people are risking their health by turning to the underground market, often via social media, to buy weight loss jabs. They are desperate, often due to recent price hikes or limited availability, but the fact is: when you buy from an unverified source, you are not buying medicine, you are gambling with your health.’

At an exclusive roundtable hosted by MedExpress, Dr Dix added that unverified weight loss drugs pose an ‘immense risk’ to patient safety due to the lack governance around them. They may contain contaminants or the wrong ingredients and there’s no clinical support for the people taking them, she said.

Dr Bryony Henderson, medical director for digital health company HeliosX Group and former GP, said unverified weight loss drugs are no different to street drugs.

The survey also found that while 90% of people trust medical or pharmacy websites more than social media for health information, the visibility of these counterfeit products online is ‘dangerously high’. More than three-quarters of the public (74%) have already seen or heard about the unregulated weight loss treatment, Retatrutide, on social media.

Clinical trials for Retatrutide are still ongoing and it is unlikely to be available in the UK until 2027, but Dr Dix said she was ‘utterly shocked’ by how widely available it was online.

‘When we were looking at this a few weeks ago, with two clicks I was able to find a whole range of websites selling this. These are quite sophisticated operations and the risks of that are immense. Something in a vial is likely manufactured incorrectly, it may have degraded during transport, it may be injected at the wrong dose and there’s no clinical support around it. You don’t know what’s in it, sometimes it probably isn’t even retatrutide,’ she said.

Roz Gittins, chief pharmacy officer at the General Pharmaceutical Council (GPhC), said: ‘Getting prescription-only medicines for weight management from unregulated sources, or friends and family, puts people at risk of potentially life-threatening side-effects.

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‘If the medicines aren’t supplied by a pharmacy that is registered with the GPhC, then the medicines may be fake. You can check if a pharmacy is registered with us by searching our registers on our website.’

Men are substantially more likely to buy unverified weight loss drugs according to the survey, with 27% of men having bought them compared to 16% of women – likely due to stigma surrounding men who use weight loss drugs, Dr Dix speculated. This is despite women forming the vast majority of MedExpress’s customers (81%).

The survey respondents were 58.6% women and 41.4% men.

Dr Henderson stressed the important role pharmacists can play in supporting patients on weight loss drugs. While they cannot prescribe weight loss medicines on the NHS, they can advise patients about the side effects of taking them and where to safely purchase them, she said.

She also said pharmacies are ‘ideally placed’ to prescribe GLP-1s on the NHS because most towns and villages have a pharmacy and from this year all new pharmacy graduates will be prescribing pharmacists after completing their foundation training year.

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‘If the NHS turned around tomorrow and said, “open the floodgates; everyone who is eligible for a GLP-1 can go and see their GP”, GPs wouldn’t cope. The whole system would be overwhelmed. And if that could be avoided by allowing community pharmacists to provide the service too then 100% absolutely do that. The issue is, who’s going to pay for it?’

In September, the National Pharmacy Association called for an NHS-commissioned weight loss jab service to relieve pressure on general practice. The call follows new survey data showing one in 25 consultations with GPs and nurses involved discussions about Mounjaro.

Tirzepatide (Mounjaro) became available to patients through their GP practices on 23 June, provided they meet the eligibility criteria. Currently, this is a BMI of 40 or above and at least four weight-related health conditions.