The Real Cost of Underground Weight Loss Drugs: A Pretty Penny in the Long Run

The popularity of weight loss medications like Wegovy and Mounjaro has skyrocketed this year, but at what cost? These medications continue to change the lives of those grappling with obesity, and scientific research suggests they are lowering risk of other health complications, such as heart disease.

However, growing demand comes at the same time as price hikes from manufacturers and ahead of widespread, national rollout from accessible sources such as the NHS. This gap may be causing an unexpected health crisis, as new research from MedExpress exposes the scale of the booming underground market for the medications.

Latest headlines have seen horror stories of patients taking unverified medications with terrible outcomes, as well as sieges of illegal stockpiles at the extent of advertising on social media networks. Unverified or underground sources include sellers on social media, unlicensed websites and informal in-person suppliers. Unfortunately, these unverified sources are all too easy to access in an age of misinformation and financial pressures.

With millions of Brits using GLP-1s, the findings reveal that one in five of them* have purchased from an unverified ‘underground’ source. What’s most worrying is that the numbers show no sign of slowing.

The scale of the problem

In November 2025, MedExpress surveyed 2,000 UK adults who are using, have previously used, or are considering weight loss medication. The results paint a concerning picture of a growing underground market fuelled by rising prices, social media visibility, and limited NHS access.

The key findings show:

• 21% have purchased a weight loss jab from an unverified source (social media or in-person sellers)
• A further 31% have considered buying from these unsafe sources
• Nearly half of high-risk users (those most likely to purchase unverified medication) have encountered offers for unverified weight loss drugs on TikTok (49.8%), Facebook (49%), and Instagram (47.9%)
• More than two-thirds (74%) have already seen or heard about Retatrutide (a weight loss drug still in clinical trials) on social media

Who is most at risk of underground purchases?

The data reveals clear patterns in those who are turning to underground sources.

Age matters

Adults aged 25-34 are twice as likely to purchase unverified weight loss drugs (29%) compared to those aged 45-54 (14%), and four times more likely than those aged 55-64 (7%). Young adults aged 18-24 are also likely to consider buying from unverified sources following recent price increases.

Gender plays a surprising role

Men are substantially more likely to buy unverified weight loss drugs, with 27% of men saying they have or would, compared with 16% of women. Even more concerning, despite being the highest-risk group, men are 18% more likely to believe claims on social media regarding weight loss medications.

Why social media is fuelling the problem

Social media has become a primary source of misinformation in the battle against the underground market. More than half of respondents first hear about GLP-1 medications through social media (54%), while 30% learn about them from influencers or content creators.

Those aged 18-24 (63%) and 25-34 (59%) are most exposed to these unverified GLP-1 medications via platforms like TikTok and Instagram. While 90% of people trust medical or pharmacy websites more than social media for health information, the sheer visibility of counterfeit products online is dangerously high.

Growing financial pressures

Recent price increases in weight loss medications have pushed many people towards risky alternatives. In fact, 64% of respondents say they have taken action in response to price changes, such as:

• 44% looked for affordable licensed options
• 12% delayed or stopped treatment entirely
• 8% considered unverified sources

Of this group, women were more likely to have delayed or stopped treatment due to price changes (14% vs 9% of men), while people aged 18-24 were more likely to have considered buying from unverified or unlicensed sources following price increases.

What are the real dangers of unverified weight loss drugs?

Those purchasing weight loss medication from an unverified source have no idea what they are actually buying, and it’s always a gamble.

Dr. Sophie Dix, Head of Medical Affairs at MedExpress, emphasises that “when taking counterfeit jabs, you risk severe harm to your health, as they haven’t been through clinical trials and are completely unregulated.”

The public does recognise the risks. Survey respondents identified the following dangers of unverified sources:

• Incorrect ingredients or doses (64%)
• No medical supervision (62%)
• Financial scams or fake sellers (61%)
• Contamination or infection (53%)

Yet individuals continue to purchase medication from underground sources. Women, however, are significantly more aware of the most serious physical dangers, and are 15% more likely than men to associate unverified sources with the risk of incorrect ingredients or doses.

Unverified medications may contain incorrect ingredients, contaminants, or be completely fake products. They will not have been manufactured to appropriate medicinal standards, and those taking them won’t receive the clinical support necessary to ensure these medicines are safe for them specifically. Without regulated support, patients are vulnerable to the following:

• No medical assessment to determine if the treatment is appropriate for their health status
• No monitoring for side effects or complications
• No support for those experiencing adverse reactions
• No recourse if the product is fake or causes harm

Why are people taking the risk?

Despite the public understanding of the dangers, the research reveals several factors pushing them to purchase unverified medication, all pointing to one large trust paradox.

Limited awareness among young people

Those aged 18-24 are less likely to be aware of the risks associated with taking unverified medication. They're also 15% less likely to trust licensed online pharmacies to provide safe medication compared to people aged 25-34.

The rationalisation gap

While 72% say they would “always” choose a licensed pharmacy over a cheaper, unverified source, 6% would actively “consider” the cheaper option. People aged 18-25 are 1.6 times more likely to rationalise this risk than the next highest age group.

The perception of safety

Worryingly, more than half believe that buying prescription medicines online without a prescription can be safe (55%). Only 40% believe it is never safe.

The trust paradox

The research reveals a troubling paradox. While an overwhelming majority deem it important that a pharmacy is licensed and regulated (96%), and feel safer buying medication from a pharmacy that requires a prescription and medical review (94%), many are still taking risks with unverified sources.

This gap between knowledge and behaviour suggests that price pressures and social media influence can be powerful enough to override people’s better judgment.

Of course, individuals also come under cultural pressures and grapple with social stigma that we should look a certain way. Often the desire to lose weight quickly can overshadow safety concerns and coupled with the increase in prices of some medications, many are looking for more affordable options, or new and exciting ‘wonder’ drugs that could be even better than what’s already on offer.

However, these are extreme solutions. Many people may not fully appreciate that underground products can contain unknown substances, may be overdosed, underdosed, or contaminated, lack medical oversight, and can cause serious health complications. Marketing often deliberately conceals or downplays these realities, especially when the drugs are unverified.

How to stay safe

If you’re considering a GLP-1 treatment, always prioritise your health over cost savings. Here’s how to ensure you’re getting legitimate medication:

• Verify the pharmacy is licensed and regulated - In the UK, legitimate online pharmacies must be registered with the General Pharmaceutical Council (GPhC). You can check this on the GPhC website.
• Require a medical consultation - Legitimate services will always require a proper medical assessment before prescribing weight loss medication. This isn't bureaucracy, it's essential safety.

Dr. Dix’s message is clear. She says: “This is a crisis of counterfeit weight loss jabs. 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."

Not only are these unverified medications unsafe, but they are illegal in the UK, as they have not been approved by the MHRA. This means their safety, dosing and side effects are not yet established and these risks far outweigh any potential benefit. It is much safer to stick with medications that have been thoroughly tested and obtained from licensed sources.

The bottom line is that health is not worth the risk of a cheaper, unverified source. If you’re considering weight loss medication, it’s imperative that you speak to a licensed pharmacy and ensure you receive proper medical consultation and support throughout your treatment journey. The few pounds you might save could cost you far more in the long run; your health is never worth gambling with, despite external pressures.

MedExpress provides licensed, medically supervised access to GLP-1 treatments. If affordability or access is a concern, speak to our clinicians; we’re here to help you stay safe and support you as best as we can through your weight loss journey.

Survey Methodology

Research was conducted by MedExpress, using Attest as the survey provider, to quantify UK consumer awareness of, engagement with, and perception of safety risks associated with purchasing weight loss drugs (GLP-1s) from unverified or illegal online/in-person sources. In November 2025, they surveyed 2000 UK-based respondents aged 18 and above.

*All participants in the survey have either used weight loss medication, previously used a weight loss medication, or are potential future users of weight loss medication.