One individual has detailed her experience obtaining and self-administering retatrutide, a potent experimental weight-loss drug, through illicit channels. The move came after a significant price increase for Mounjaro, a previously effective weight-loss medication she was prescribed.
The substance, known as 'reta,' is not yet approved by regulatory bodies like the UK's MHRA and is being sourced from unofficial dealers, often found on platforms like WhatsApp. The individual described receiving a package containing vials, syringes, and needles, with no instructions, describing the situation as the "Wild West of unregulated and illegally supplied fat jabs."
She had been using Mounjaro since February 2025, achieving substantial weight loss with no adverse effects. However, the price of her prescription doubled from £150 to £300 per month. While she had reached her target weight, the fear of regaining pounds, a common challenge with these drugs, motivated her search for alternatives. She also utilized a "microdose" strategy with her remaining Mounjaro pens and took up running.
The crackdown on her Mounjaro supply by her online pharmacy, which began questioning her continued need for the prescription based on her weight, further pushed her toward illicit options. A casual conversation led her to a dealer named "Jim Slim" on WhatsApp, who sourced the drug from what he described as an industrial-scale Chinese laboratory.
Retatrutide, developed by Eli Lilly, is a synthetic peptide currently in clinical trials. It targets three receptors—GLP-1, GIP, and glucagon—influencing appetite, blood sugar, and energy use. Clinical trials have shown significant weight reduction, with the highest studied dose leading to a mean loss of 28.7 percent over 68 weeks. The drug is sometimes referred to as 'Triple G' for its multi-receptor action.
Sellers often circumvent regulations by labeling such products as 'for research use only,' though selling them as weight-loss injections is illegal. "Jim Slim" claimed his product had 99 percent purity and offered a certificate of analysis, though the authenticity and value of such documents from unaccredited labs are questionable. The dealer was unwilling to disclose his supplier.
The process of preparing and self-injecting retatrutide proved complex and daunting. It requires mixing a powder with sterile 'bac' water, a process demanding precise measurements that the user found challenging, as she had failed mathematics in school. Unlike pre-filled Mounjaro pens, this involved using provided syringes and needles, which she described as resembling "Victorian torture implements."
Experiencing side effects, she noted overwhelming fatigue from the outset, along with intense thirst and dry mouth. She also reported a chronic pain in her left side during the first month, which led to an emergency room visit and a diagnosis of suspected diverticulitis. Medical professionals expressed disapproval of her self-administered treatment, with one doctor reportedly remarking on her "unnecessary risk."
Despite the risks and side effects, she stated her intention to continue using the drug to maintain her current weight, finding the psychological benefits of her weight loss transformative. She expressed a willingness to do "almost anything" to stay thin, acknowledging the perceived irresponsibility of her actions but emphasizing the positive impact on her happiness and self-esteem.
Experts caution against using such unregulated substances. Dr. Jack Mosley, author of 'Food Noise,' highlights that black market GLP-1 drugs, including retatrutide, are unlicensed and potentially dangerous. Buyers may receive incorrect doses, different medications, or products contaminated with impurities or bacteria. These counterfeit versions, often manufactured in China, India, and Russia, pose significant health risks, likened by Dr. Mosley to "playing Russian roulette with your health."
Retatrutide is projected to be a candidate for regulatory review by health authorities in early 2027. The potential approval could lead to increased costs, creating further challenges for individuals relying on the drug for weight maintenance.