A leading consumer researcher has issued a stark warning about the "wild west" of online weight loss supplement claims, branding many as completely untrustworthy and, in some cases, absurd.
The 'Wild West' of Online Supplement Claims
Megan Thomas, a researcher for the advocacy group Which?, has detailed her findings on the widespread and often unsubstantiated promises made by sellers of diet pills and similar products. Speaking on the organisation's podcast, she stated that many claims should simply "not be trusted" by the public.
Her investigation revealed a landscape where specific, legally-approved health claims are routinely stretched or ignored. "You can't just say things willy-nilly," Thomas noted. She highlighted common assertions like "fat burner" or "appetite suppressant" on products whose ingredient lists provide no justification for such effects, a problem she says is rife on online marketplaces which are hard to regulate.
Thomas also pointed out that even major retailers sometimes push the boundaries, taking a legitimate claim—such as an ingredient contributing to normal metabolism—and "stretching it out" to imply it directly aids weight loss.
'Burns Fat in Five Seconds': Examples of Egregious Promises
During her research, Thomas catalogued some of the most outrageous claims designed to lure consumers. "Some of the most egregious are just like completely absurd," she said, offering examples that should be easy for shoppers to spot as false.
These included promises that a product "burns fat in five seconds" or guarantees that users will "have lost centimetres off your waistline" within a week. She also identified terms like "fat burner," "appetite control," and "appetite suppressant" as frequently used without any scientific evidence to back them up.
One ingredient singled out was green tea, which appears in "loads of these supplements." Thomas clarified that while it has certain properties, it is often inaccurately promoted as a potent fat burner.
No Substitute for Regulated Medicine, Expert Warns
The warning comes amid significant public interest in weight loss solutions. A study in the British Medical Journal estimates that approximately 1.5 million people in the UK now use weight loss injections. An Ipsos survey for the Press Association found that 26% of adults would only use such jabs if prescribed by a doctor, with 16% open to getting them from a pharmacy.
Alarmingly, the same survey discovered that 9% would consider purchasing them through social media platforms, where advertising is prolific and often poorly monitored.
Consultant dietitian Sophie Medlin echoed Thomas's concerns, explaining that the success of prescription GLP-1 medications like Ozempic and Mounjaro has spurred a flood of supplement alternatives claiming to mimic their effects. "The market's now flooded with ones that are supplements that are pretending to be mimicking GLP ones," she stated.
Medlin delivered a crucial reminder: "There's no registered health claims for any weight loss supplements." She emphasised that any product asserting it can "support" or "aid" weight loss is likely making an illegal claim. These injectable medications, she clarified, are distinct pharmaceutical products licensed for specific conditions and work in a very different way to over-the-counter supplements.
How to Report Misleading Adverts
Both experts stress the importance of consumer vigilance and action. Medlin advised that misleading claims can and should be reported to the Advertising Standards Authority (ASA).
The ASA accepts complaints from the public, competitors, or interested groups about adverts seen online or elsewhere. Complaints can be submitted via a dedicated online form on the ASA website. A separate form is available for reporting suspected scam advertisements.
By raising awareness and reporting false claims, consumers can help regulate an industry that currently operates with too little oversight, protecting others from spending money on ineffective and deceptively marketed products.
