About two years ago, Henry, who is 6ft 3in, weighed 210lb, which meant he was only slightly overweight, according to the Centers for Disease Control and Prevention body mass index.

Still, the thirtysomething who lives in the Pacific north-west had hypertension, sleep apnea and body image issues, so he started taking the weight-loss drug Ozempic. While he dropped pounds, he experienced constipation, a common side-effect, so he wanted to try retatrutide, another peptide which not only targets GLP-1 but two other hormone receptors as well.

He had read about it in the news and on Reddit forums.

The problem is, the US Food and Drug Administration has not approved the drug, so Henry bought it online from sellers in China.

Henry, who did not want his last name used, is among a growing number of people dissatisfied with the revolutionary weight-loss drugs that can be obtained legally with a prescription and have instead turned to the gray market to purchase retatrutide, which is manufactured by the pharmaceutical company Eli Lilly and is being studied in clinical trials.

Physicians see the drug as a promising potential solution for people struggling with obesity, but strongly warn patients that they are seriously risking their health by using it without oversight from doctors and government regulators. Yet these warnings often go unheeded.

“All of these medications should be monitored and prescribed in a medical situation where the doctor or the clinic is partnering with the patient on a complete plan” including “monitoring their lab [work], their vital signs, their response”, said Dr David Shafer, a plastic surgeon in New York who takes the drug. “It’s really the self-prescribing and unknown usage that is leading to a lot of the problems.”

Retatrutide could work well in helping people lose weight – and potentially have other health benefits – because whereas Ozempic targets one receptor, and tirzepatide, sold as Mounjaro and Zepbound, targets GLP-1 and the receptor GIP, the newer drug is a “triple agonist”, meaning it targets those two receptors and glucagon, which speeds up the body’s metabolism and helps it break down fat cells for energy.

Counterfeit retatrutide seized in UK raid in October 2025. Photograph: MHRA

In an 80-week clinical trial, patients with severe obesity and heart disease taking the highest weekly doses of ⁠retatrutide achieved an average weight loss of 22%, or 55lb, according to Eli Lilly.

“The more natural gut hormones that you upregulate, the more weight loss we see,” said Dr Caroline Messer, an endocrinologist in New York.

If a patient were to ask Messer whether she recommends the drug, she would say: “Wholeheartedly – but not through the gray market. Just wait till it hits the market.”

Patients, in fact, ask Messer about retatrutide about five times daily, she said.

Most of them “have maxed out on Zepbound and still are not at their target weight, but it’s also people who enjoy being at the cutting edge of things”, she said.

A Reddit group dedicated to the drug gets more than 179,000 visits each week.

The demand for the drug is “concerning because of the way it’s been popularized through podcasts and politicians, not through doctor-patient relationships”, said Dan Burke, a former division chief of the US Food and Drug Administration office of criminal investigations.

In August, Eli Lilly announced it would provide a limited number of patients access to the drug before the FDA approves it, Reuters reported.

But Messer said that while the process is supposed to help patients “who are desperate” to try the drug, it is “just so unbelievably difficult” to qualify for special access that it could take years to obtain it, by which time the FDA will likely have already approved it.

“It pits the patient against the doctor because now the patient thinks that we are not doing everything we can to get them the medication, where it’s really actually just this super-onerous process,” Messer said.

As such, patients are finding other ways to obtain the drug. The Reddit group features a “beginner’s guide” to getting it through the gray market and encourages people to “find communities (not on Reddit)”, “get tapped in” and “vet vet vet like your money depends on it”.

The guide also provides instructions on dosing and warns people not to use the product if it comes in a prefilled pen.

Eli Lilly recently filed lawsuits against six companies that allegedly sold the drug, including Lone Star Peptide, which is based in Texas and markets the drug for “research use only”, and Aesthetic Envy Cosmetic Centers, a med-spa in Sacramento, California.

A person who answered the phone at Lone Star Peptide declined to comment. Aesthetic Envy did not respond to a request.

“Illegal drugs made outside of a regulated, inspected supply chain are more likely to contain bacteria and other harmful contaminants and impurities. Consumers have no way to know whether these products are safe or effective,” a lawsuit states.

Messer argues that obtaining the drug through the gray market is potentially dangerous because patients do not know how much of the drug the product contains or its purity. In June, the Victoria state government in Australia reported six cases of acute liver toxicity among patients who consumed a product labeled as retatrutide.

“This is something that you are injecting, and you don’t know where it’s being made,” Messer said.

Despite warnings from physicians and government agencies, patients are still buying the drug on the gray market – and at least sometimes getting their desired results.

“The ones who have plateaued on tirzepatide [Zepbound] are starting to lose weight again, so losing an additional 20 to 30lb,” Messer said.

Henry has not told his doctor he is taking retatrutide because he did not want documentation of it, he said.

But he has lost 30lb since starting on it and is “doing good”, even though his skin has become extra sensitive, a common side-effect of the drug.

“For the first time in my entire life, I feel like I am in control of my body,” said Henry, who also now drinks less alcohol.

Shafer, the plastic surgeon, said that even if people are not obtaining retatrutide from a prescription, they should disclose their use of it to their provider.

“The doctors are not the police, and they are not going to turn you in for buying something online,” Shafer said. “The doctor and the patient can partner together to formulate the best plan.”

Shafer said he started taking a GLP-1 agonist because he wanted to lose about 20lb for health and aesthetic reasons. He then started taking retatrutide because his weight loss had plateaued, and also because he expected to someday prescribe it to patients and wanted to see how it worked. He obtained it from a compounding pharmacy, which prepares medications on site.

He said it not only helped him lose weight but improved his muscle tone and reduced his blood pressure, which had been slightly elevated.

Shafer argues that the FDA should expedite its review of it.

“I don’t think it’s something that should take 10 years for them to do studies on,” Shafer said. “Then you’re going to have all these other people that are doing it anyway off the black market, and who knows what it is they are taking.”