DODGY fat jabs are the new steroids say experts — pointing to a booming black market for gym users.

People are increasingly turning to super-powered slimming injections to boost workout gains and get ripped muscles.

Young man doing squats with a kettlebell in a gym.Gym goers are turning to super-powered slimming injections to boost workout gains Credit: PeopleImages Illustration of a vial labeled "Retatrutide 12 MG" and "99% Purity".Retatrutide has become wildly popular despite not yet being legal to use Credit: Alamy Stock Photo

And one experimental jab called , known online as “reta”, has become wildly popular despite not yet being legal to use.

It is still in clinical trials but shady websites use a legal loophole to rip off the ingredients and sell the jab for “research purposes”.

This had led to a roaring trade online despite no guarantee the product is not counterfeit or contaminated.

People often portion out the drug at home without knowing what is really in it — and inject themselves as they might with anabolic steroids.

Dr Luke Turnock, a performance-enhancing expert at the University of Lincoln, said: “In terms of distribution and prominence in gym culture, ‘reta’ is absolutely following the pattern of steroids.

“It may be one of the most ­prevalent out there right now.

“Not only are gyms full of reta users, but it is also being sold by various beauty clinics, beauty pages, and social media accounts.”

Research by MedExpress found men aged between 25 and 34 are most likely to buy the drug illicitly — unlike the regulated market, where women are the majority.

Research also found half of high-risk users get adverts for the drug on and .

Other studies suggest retatrutide will be even stronger than legal jabs such as Wegovy and Mounjaro.

MedExpress’s Dr Sophie Dix said: “ may be more effective at targeting fat stores while helping to preserve lean muscle mass — a major concern for athletes.”

Both she and Dr Turnock strongly warned against injecting untested medicines at home.

Dr Turnock added: “Retatrutide is still an experimental so may have long-term risks that are not yet fully understood.

“Even if it does pass all clinical trials, the illicit market product will still have risks because purity is uncertain and doses recommended by sellers may be risky to use.”