The next weight-loss drug is here — but it’s fake and untested

Holbrook, however, is not waiting for the official version. He and many other British slimmers and bodybuilders, desperate for the advantage the new drugs can give them, are using an illegal counterfeit version, made in Chinese labs and bought online.

“I know it all comes from China and that it’s risky since it hasn’t been cleared yet,” Holbrook said. “But you see it online and everyone is doing it.”

Experts warn that taking any counterfeit drug, let alone a copy of an unproven drug, is highly dangerous. “People who purchase counterfeit or black market medicines have no way of knowing what they actually contain,” an Eli Lilly representative said. “They aren’t tested, have no regulatory oversight for safety, quality or efficacy, and can pose a serious risk to patients.”

Andy Morling, head of criminal enforcement at the Medicines and Healthcare Products Regulatory Agency (MHRA), said drugs should only ever be taken if obtained from a pharmacy. Sourcing drugs “in any other way carries serious risks to your health — there are no guarantees about what they contain, and some may even be contaminated with toxic substances”, he said.

But users are ignoring the warnings, egged on by social media posts that extol the drugs’ virtues. Policing this is a challenge. For every video that is taken down another one appears.

‘Engineered to exploit our frailties’

TikTok features hundreds of videos of young slimmers, particularly teenage bodybuilders, saying how much weight they’ve lost by taking the drugs. In the comments, sales managers in China encourage users to buy direct and reply to users asking where to buy it.

“TikTok’s algorithm is like a homing missile,” said Imran Ahmed, from the Centre for Countering Digital Hate. Social media, he warned, is overwhelming teenage boys with images of physiques that are impossible to achieve without peptides and steroids. “It is engineered to precisely target people with content that exploits their psychological frailties.”

Sukhi Basra, vice-chair of the National Pharmacy Association, said: “These children are not watching the news — they get all of their information from TikTok. Regulators need to recognise this and use those same mediums to re-educate teenagers and keep them safe.”

Retatrutide is sold openly online

Studies show that men’s body image anxieties tend to centre on muscularity, not thinness. On social media, “biohacking” has become mainstream and retatrutide is the holy grail — a compound that promises to torch fat while preserving muscle, making you both lean and strong.

“Peptides are very popular with vulnerable young people,” says Dr Nihara Krause, a clinical psychologist. “A lot of these drugs promote a quick fix and if you’re a teen, or desperate to belong and feel admired, then that quick fix is extremely appealing.”

Jack, 16, a bodybuilding enthusiast from Essex, says retatrutide is “famous” among his friends. “Social media glorifies it, and you hear influencers and content creators say your whole life will change if you just take this,” he said.

A 19-year-old weightlifter, who asked not to give his name, said social media had convinced him he should be taller and leaner, even at 6ft 3in. He said: “Everything I’d scroll would be someone promoting it and saying all you need are these peptides to reach your goals. It still sits in the back of my mind now about taking things to boost my attractiveness.” He said he had been tempted to buy retatrutide but had decided against it at the last minute.

Another young man, a 29-year-old fitness enthusiast, said he has lost two stone since taking retatrutide since April. He said: “It all comes from China. You find the labs on forums and you can join Telegram [messaging app] groups with other people and do bulk orders.”

On fitness forums some users admit they have suffered from side-effects. “I’ve been on reta since the end of July and everything was going perfectly until about a month ago,” said one user. “A pain in my upper left abdomen and chest appeared suddenly, like behind my ribs. I’ve also noticed that I go very faint when getting up too quickly. My libido has also [been] very low.”

How the fakers get away with it

A key problem is that it is relatively simple for counterfeiters to make the drugs.

Richard Bayliss, a chemist at the University of Leeds, said synthesising a peptide like retatrutide is as easy as following a recipe. “Once the chemical structure is published, an experienced chemist can figure out how to make it, just like how a skilled chef with a well-equipped kitchen would be able to follow a recipe they didn’t invent,” he said.

Retatrutide’s chemical structure was made public in an open-access academic paper in 2022, and the following year Eli Lilly published early data suggesting that the drug reduced body weight by up to 24 per cent in 48 weeks. Counterfeiters started churning out copies of the drug.

Some companies say they sell the drug as a research chemical only, benefiting from a loophole that allows sellers to advertise, sell and ship products to customers without following the rules that apply to medicines. But others are openly marketing and selling the drugs as weight-loss treatments, breaking UK law. Because retatrutide is not a controlled substance, taking it is not illegal — but it is certainly inadvisable.

One website used by Chinese companies to advertise to western buyers has 8,000 listings for retatrutide, offering a month’s supply for as little as £20. One Chinese seller told The Sunday Times that clearing customs was not an issue. “We have many UK customers and haven’t had any parcels to England that have been stopped,” they said. “It will be transported by Royal Mail after customs clearance, and if the package is detained, we will reissue, free of charge.”

British counterfeiters are also in on the act. Last month the MHRA closed an illicit production facility outside Northampton in what officers believe was the largest single seizure of trafficked weight-loss medicine ever recorded. They seized tens of thousands of empty weight-loss pens, raw chemical ingredients and more than 2,000 unlicensed retatrutide and Mounjaro pens awaiting dispatch to customers.

But tackling the Chinese operations is far harder. “I can’t even begin to imagine how you can police this online,” Basra said.

Chris Pereira, an expert on China’s manufacturing operations, said tackling counterfeiters was almost impossible. “They will disappear right after they’re done selling. Even if the websites get closed down, three more would pop up instead.”

TikTok said it did not allow trading, marketing, or providing access to regulated, prohibited, or high-risk goods and services, including products marketed for weight loss or muscle gain. The company said posts that breach these guidelines are taken down.

Eli Lilly said counterfeit drugs “may contain no active ingredient at all, or contain other harmful ingredients,” adding: “No one should ever risk putting them into their bodies. Lilly has taken steps to help address the risks posed by counterfeit, fake and other illicit products across the world, including working with regulators and law enforcement, and identifying and removing fraudulent or unsafe content online and on social media.”

Additional reporting by Ben Spencer, Science Editor