Erin, a 29-year-old single mother of three from Dartford, Kent, embarked on a weight-loss journey in January after experiencing significant life changes. With a BMI of 31, classified as obese by the NHS, she initially tried semaglutide, the active ingredient in Ozempic and Wegovy, sourced online. Despite increasing the dose over three months, she felt 'defeated' as her weight remained unchanged. She then switched to Mounjaro, acquired through a friend, but encountered the same lack of progress after five months.

Her attention was soon drawn to a new, purportedly 'miracle' weight-loss drug, retatrutide, which began flooding her TikTok feed. Users claimed this powerful slimming drug, said to be stronger than anything else on the market, could achieve weight loss where Wegovy and Mounjaro had failed. Erin was eager to try, having struggled with her weight for years, especially after having twins and a recent separation.

However, there was a significant catch: retatrutide, manufactured by Lilly, has not yet completed clinical trials and is not expected to hit the global market until late 2026 or more likely 2027. Despite health experts uniformly urging against unapproved supplies due to grave risks, Erin acquired the drug—also known as 'Reta,' 'Ret,' or 'Triple G'—from a beautician friend who claimed to have 'contacts.' Erin acknowledged her worry about buying it online but trusted her friend, believing she would not suffer significant side-effects as she hadn't with semaglutide or Mounjaro.

Her initial experience with retatrutide was not without incident. After her first injection, Erin suffered severe cramps that woke her during sleep and a bad headache two days later, though these symptoms eventually subsided. She avoided consulting her doctor to avoid being 'told off.' Erin, who is scared of needles, relied on others to help her administer the injections, typically in the stomach. She reported reduced eating and fewer cravings in the days immediately following the injection, though the effects would wear off by day four, five, or six.

A month into using Reta, Erin reported a loss of 6lbs (2.8kg), dropping from 14st 12lbs (94.4kg) to 14st 6lbs (91.6kg). She hoped to increase her dose after a couple of months and looked forward to fitting into her old clothes again. Her friend also uses retatrutide for weight maintenance, taking a dose after holidays to manage weight fluctuations.

Medical professionals, however, strongly caution against following Erin's path. Purchasing weight-loss injections online or via the black market carries immense dangers, including exposure to contaminated or counterfeit versions. Previous incidents have seen black-market Mounjaro and Ozempic laced with rat poison and even cement, leading to severe health issues like seizures and comas. Border officials have intercepted dangerous 'DIY' injection kits, highlighting the risks of mislabelled and potentially lethal chemical compounds.

The real retatrutide, currently in clinical trials, is designed to target three hormones involved in eating and weight regulation—GLP, GIP, and glucagon—which not only suppress appetite but also boost metabolism. This mechanism is more comprehensive than Ozempic (one pathway) or Mounjaro (two pathways). Early Phase II trial results have been astonishing, earning retatrutide the nickname 'Godzilla' of weight-loss drugs. Patients on the highest dose lost an average of 24 percent of their body weight in under a year, surpassing the efficacy of tirzepatide (Mounjaro) at 21 percent over 72 weeks and semaglutide (Wegovy/Ozempic) at 15 percent. Notably, retatrutide also appears to help preserve lean muscle mass.

Despite these eye-catching results, the rapid and significant weight loss has also sparked alarm among doctors. Reports from clinical trials indicated some patients lost so much weight so quickly that researchers had to lower doses or instruct them to consume more calories. Such extreme weight loss carries its own risks, similar to bariatric surgery, including malnutrition, gallstones, and kidney problems. While retatrutide's muscle-preserving ability may mitigate some harms, doctors stress the need for much more data to confirm its long-term safety. Critics worry about pressure to push doses to the limit for dramatic results in the race to market new drugs, though Lilly insists on close monitoring of trial participants.

Nevertheless, retatrutide's buzz has grown on social media platforms like TikTok, YouTube, Reddit, and Instagram, especially within fitness communities. People are buying powdered forms of what is believed to be retatrutide from 'research labs' online, often with packaging explicitly stating 'not for human use.' Reddit forums provide advice on sourcing and dosing. Individuals like Erin's friend also facilitate black market sales in person. Regulatory bodies like the MHRA and FDA, alongside Lilly, have repeatedly warned against purchasing illegal retatrutide and advocate for obtaining medicines solely from licensed pharmacies with valid prescriptions. TikTok has also started banning promotional videos. Despite these warnings, Erin believes that if her experience is any indication, retatrutide's popularity is only set to rise.