Mother-of-four Shona Sibary has turned to buying an unapproved weight-loss drug from an illegal WhatsApp dealer after the cost of her legal Mounjaro injections doubled.
Sibary, 55, bought retatrutide, an unregulated triple-action peptide shot known as "reta" and dubbed the "Godzilla" of weight-loss drugs, after struggling to maintain her target weight. The drug is currently undergoing clinical trials and has not been approved by the US Food and Drug Administration (FDA).
The decision followed a price increase that saw Sibary's monthly out-of-pocket cost for Mounjaro double from $203 to $406. While monthly Mounjaro costs can reach $1,100 for some patients in the United States, Sibary faced a supply restriction from her online pharmacy after spending nearly $5,400 over 17 months. The pharmacy demanded video calls of her standing on scales and refused further orders, informing her that she had already reached her target weight.
Sibary, who is 5ft 7in tall, originally began taking Mounjaro in February 2025 at a starting weight of 173lbs (78.5kg). She lost 42lbs in six months with no side effects, reaching her target weight of 132lbs (60kg) by July, a figure she had not seen since her wedding dress fitting in 1999.
To maintain her slim frame, Sibary began microdosing tiny amounts from a stockpile of Mounjaro pens kept in her fridge over the past eight months alongside a new running routine. Her weight fluctuated between 128lbs (58kg) and 134lbs (61kg), giving her a body mass index of 20, well within the healthy range of 18.5 to 24.9. However, when her pharmacy cut off her supply, intense hunger returned, prompting her to search for alternative options.
Buying retatrutide from an unregulated online seller
In June, a mutual acquaintance who works as a wealth portfolio manager gave Sibary the contact details for a WhatsApp seller operating under the name Jim Slim. The acquaintance explained that many women were purchasing retatrutide under the counter at a peptide shop in Barking before finding cheaper dealers online.
Jim Slim offered Sibary a four-week supply of retatrutide powder for $176, significantly less than the price of regulated weight-loss injections. He advised her to start on a 2mg dose and titrate, or gradually increase the dosage strength every four weeks, to minimize potential side effects.
Two months ago, an unmarked jiffy bag containing retatrutide powder, sterile bacteriostatic water, syringes, and long needles arrived in Sibary's mailbox. The package contained no instructions explaining how to mix or inject the drug.
Preparing the injection required Sibary to carefully mix the powder with the bacteriostatic water, which prevents bacterial growth inside the fridge-stored vial for at least four weeks. Sibary described the process in her kitchen as an unsupervised science experiment, admitting she found it difficult to calculate precise liquid volumes using syringes.
Jim Slim sourced his retatrutide in bulk from an industrial-scale laboratory in China. While purchasing retatrutide is not explicitly illegal for buyers, selling the unapproved compound as a weight-loss injection or supplement is a criminal offence. Unregulated sellers across TikTok and Reddit frequently label vials for research use only to bypass medical laws.
When questioned by phone about the chemical composition and origin of his product, Jim Slim refused to put details in writing. He claimed the drug had 99 percent purity and offered a certificate of analysis, though certificates from non-accredited laboratories carry no official verification. He also offered before-and-after customer photos in place of regulated references.
Severe side effects and hospital treatment
Unlike her experience with Mounjaro, which only caused mild constipation and suppressed hunger, retatrutide produced severe physical side effects. Sibary experienced overwhelming fatigue comparable to the early stages of pregnancy, restless nights filled with intense dreams, and persistent dry mouth throughout the day.
The exhaustion was so severe that Sibary had to sleep across the back seats of her car while her 17-year-old daughter Dolly attended a university interview.
During her first month taking retatrutide, Sibary developed severe chronic pain on the left side of her stomach. After enduring the pain for two days as it worsened, she attended an emergency department in the middle of the night and was diagnosed with suspected diverticulitis, a condition where small pouches form and push outward through weak spots in the colon wall.
Medical staff expressed strong disapproval after learning of her unregulated drug use. Sibary recalled hearing the attending doctor tell a colleague he would treat her like a ketamine addict because she was putting her body at unnecessary risk. Her daughter Dolly, a student paramedic, noted that emergency call handlers now routinely ask patients with stomach pain if they are using weight-loss injections.
Sibary's husband, Keith, and several friends have warned her that she is now too skinny. Despite the medical scare and family concerns, Sibary remains on the lowest 2mg dose of retatrutide and plans to order another supply from Jim Slim to avoid regaining weight.
How retatrutide works and regulatory progress
Retatrutide is a synthetic peptide currently being developed by pharmaceutical company Eli Lilly, the manufacturer of Mounjaro. Dubbed Triple G, the treatment targets three separate hormone receptors: GLP-1, GIP, and glucagon receptors, which work together to regulate appetite, blood sugar, and energy usage.
In clinical trials, patients taking the highest studied dose of retatrutide achieved a mean weight loss of 28.7 percent after 68 weeks, representing the largest average weight reduction reported for any weight-loss medication to date. Eli Lilly is currently conducting phase three trials and plans to apply for official regulatory review with health authorities in early 2027.
Medical warnings over illicit weight-loss injections
Dr Jack Mosley, author of Food Noise, published by Short Books for $5, warned that buying retatrutide from unregulated sellers presents severe health risks. He explained that first-generation semaglutide drugs like Ozempic target a single GLP-1 receptor to achieve a 15 percent weight reduction in diabetes and obesity studies, while dual-receptor tirzepatide drugs like Mounjaro achieve 20 percent weight loss.
Mosley noted that while retatrutide's triple-action mechanism yields weight loss comparable to bariatric surgery, the drug remains unlicensed. Black-market versions sold through gyms, beauticians, TikTok, and Reddit as research chemicals not for human consumption are frequently manufactured illegally in China, India, and Russia.
According to Mosley, individuals buying unapproved weight-loss treatments online risk receiving incorrect dosages, contaminated products containing dangerous bacteria, or entirely different drugs. He highlighted reports of patients being hospitalised after injecting insulin sold fraudulently as GLP-1 injections, warning that illicit buyers are playing Russian roulette with their health.
