Julian Becerra first learned about retatrutide while scrolling social media. The 24-year-old saw Dawson Weiss, a bodybuilder, post unbelievable photos on TikTok — his muscles rippling, his torso concave. Weiss wrote in a caption: “The biggest thing I’ve noticed since taking retatrutide is the fact that it’s a challenge to actually gain fat — not gain weight, but gain body fat.”
Becerra (“not a bodybuilder by any means at all, but I do like to look good with my shirt off”) bought himself a powder labeled “retatrutide” online, mixed with water, then injected it into his muscles with a syringe, just as Weiss and other bodybuilders online described. For about a month, Becerra injected half a milligram a week. He was sold. He said he lost the urge to snack, but still had energy to work out. Eventually, he started posting his own mirror selfies on his socials. His muscles popped, and the views soared.
Retatrutide is a GLP-1 drug, in the same family as Ozempic (semaglutide) and Mounjaro (tirzepatide). It was developed by the pharmaceutical giant Eli Lilly, and it is unique because it mimics three hunger hormones (GLP, GIP, and glucagon), while similar drugs on the market target one or two. In theory, that means more staggering weight-loss results and potentially other benefits. Doctors and researchers are already jokingly referring to retatrutide as the “King Kong” for weight loss because early results in clinical trials suggest it rivals bariatric surgery, and it seems to protect more lean muscle mass.
Here’s the catch: Eli Lilly has not yet finished clinical trials on retatrutide. The earliest it could hit the market would be late 2026, though it’s more likely to drop in 2027. It’s widely regarded as a crucial piece in Eli Lilly’s strategy for taking the lion’s share of the world’s $100 billion weight-loss drug industry. Currently, it is not approved by the US Food and Drug Administration, so doctors can’t prescribe it and pharmacies can’t sell it.
And yet, over the past year, retatrutide has been gaining traction on TikTok, YouTube, Reddit, and Instagram, particularly in fitness circles. People chasing chiseled physiques buy powder labeled “reta” or “ret” online from research labs, which are legally allowed to manufacture compounds for research only. Their products come with a caveat that they are “not for human consumption.”
These consumers appear comfortable mixing their drugs up themselves. They describe reta as a “next-gen” GLP-1 drug, saying the injectable they are taking helped them cut fat and get lean without the muscle wasting that many people experience on Ozempic, Wegovy, Mounjaro, or Zepbound. They post eye-popping photos and videos as proof and marvel at the appetite-suppressing power of this new injectable peptide. Reddit threads are filled with questions and advice on which labs to avoid for safety and how to dose the drug depending on your goals. People describe asking ChatGPT to personalize the advice.
This is the next era of the GLP-1 boom. Post-Ozempic, the gray market for unofficial weight loss solutions is taking on a life of its own among people who are highly skeptical of the healthcare institutions normally involved in drugmaking and prescribing.
There are crackdown efforts: The US Food and Drug Administration says people should buy their drugs from licensed pharmacies, with valid prescriptions. A Brookings report earlier this year showed the majority of counterfeit GLP-1s come from wholesale manufacturers in China, outside of US oversight. The FDA is trying to catch knock-off drugs at the border with limited success. TikTok recently started banning videos that promote retatrutide. Doctors say they are warning their patients that they have no idea what they are getting. Unregulated drugs are often inconsistently dosed and have been found to carry contaminants like formaldehyde.
Drugmaker Eli Lilly told Business Insider in a statement that “anyone purporting to sell retatrutide for human use is breaking the law.” The company added: “No one should consider taking anything claiming to be retatrutide outside of a Lilly-sponsored clinical trial.”
Still, the trend persists. Creators make new profiles, labs fly under the radar. Big pharmaceutical companies, government regulators, and doctors have little power to intervene as people look to DIY their way into new bodies.
In search of weight loss drugs, without the high prices or FDA oversight
Around 2023, GLP-1 knock-offs entered the mainstream via regulated, US-based compounding pharmacies. People couldn’t access the brand-name weight-loss drugs like Ozempic and Mounjaro because high demand triggered shortages. So they turned to compounders, which have legal discretion to make cheaper versions of approved drugs when access is limited.
That opened Pandora’s box. Patients were presented with the option to get their life-changing weight-loss medication for way less than $1,000 a month, side-stepping insurance. Plus, people who weren’t eligible for GLP-1 prescriptions because they didn’t have diabetes or obesity were able to get their hands on compounded versions through telehealth companies that asked very few questions.
People came to dread the end of the drug shortages, knowing the FDA and pharma companies could then crack down on their beloved compounded dupes.
Cue research labs. Unlike compounding pharmacies, they exist outside the realm of pharmaceutical regulation. Because they’re not making products for human consumption, they’re not subject to rules about what they can offer and when, based on shortages, drug approvals, or patent status.
The practice took off in the summer of 2024. Anecdotal evidence suggests websites selling research peptides were increasingly catering to gymgoers, selling peptides that promise to tan skin, curb hair loss, and — yes — cut fat. There was an extremely low bar to entry: See a video, click a Linktree, get the product. Some sites offer the bacteriostatic water and syringes people need to mix their own dosages at home. It’s a lot like shopping on Amazon, if a bit more chemically technical.
Mr. Olympia competitor Nick “The Mutant” Walker posted about retatrutide earlier this year, saying he had tried it out before a couple of big bodybuilding shows and it worked “tremendously” to shred fat. (He won the men’s open division of the New York Pro 2025 bodybuilding competition in May.) Derek Munro, the bodybuilder who produces the podcast “More Plates More Dates” and has appeared on Joe Rogan’s podcast, was another early pioneer.
Max Radovanic lost 230 pounds over a period of about two and a half years, first by dieting, then with assistance from semaglutide and retatrutide. He first heard about reta from Munro, a few months after his insurance kicked him off his semaglutide pill, Rybelsus. He said he no longer qualified for the drug because he’d successfully lost more weight and controlled food noise using it. That was frustrating, and the 22-year-old panicked, worried about a rebound. With a few clicks on a peptide website, he said he was able to find compounded semaglutide and then retatrutide.
He was so enamored with his own results, he started selling reta. He buys medications in bulk from a research lab online. Then, out of a warehouse in Colorado, he packs and sells various blends and “stacks” — combinations of peptides, including GLP-1s, that purportedly offer different benefits for muscle growth, healing, and weight-loss. It’s all labeled for “research use only.” Alongside reta, he lists another not-yet-for-sale drug from Novo Nordisk, called cagrilintide, or cagri, and a popular concoction: cagri-reta, blending two in-development GLP-1s from two different drugmakers. In just a few months, Radovanic says he’s amassed thousands of customers across North America.
Radovanic isn’t alone. Becerra, the 24-year-old mentioned earlier, is passionate about optimizing men’s hormones, as part of a bigger quest to boost testosterone, masculinity, and male self-confidence.
After buying and trying the drug himself, he saw the potential. He teamed up with a friend to cofound Overtime Men’s Health in Tampa, Florida, joining the blossoming industry of men’s health clinics. They source retatrutide from a compounder’s “sister company” that is “in place because of the FDA restrictions,” Becerra said. They sell it online alongside a smorgasbord of products that promise to nourish masculinity — testosterone, creatine, and peptides like BPC-157.
The groups that oversee compounding in the US, the Alliance for Pharmacy Compounding and the Outsourcing Facilities Association, told Business Insider that anyone getting retatrutide from a clinic or a lab should know that it is not compounded or regulated. They said compounding pharmacies play no role in this trade since retatrutide is not an approved drug.
Novo Nordisk, the company behind Ozempic, told Business Insider: “Attempts by compounders to evade the law or abuse so-called ‘grey-areas’ are not in the best of interests of patients as well as undermine the US supply chain, US manufacturing and US jobs.”
In February, 38 state Attorneys General asked the FDA to “stop the bad conduct” by counterfeit drugmakers. The FDA told Business Insider in a statement that it is “actively working” to protect consumers from counterfeit GLP-1s through “public awareness, enforcement actions, and collaboration with other agencies.”
Last spring, FDA Special Agents worked with the Department of Justice to arrest a woman in New York for selling fake Ozempic and pressed charges against a doctor in Kentucky who was selling “lab research” semaglutide, calling it “Meal Prep” in Venmo payments. The FDA also said it has been working with Customs and Border Protection, “intercepting illegal products at ports.” Business Insider has seen photographs of stashes of semaglutide hidden inside bags of kitty litter and antiaging face masks from China.
The FDA is unequivocal that “retatrutide and cagrilintide cannot be used in compounding under federal law.”
“These are not components of FDA-approved drugs and have not been found safe and effective for any condition,” the agency said in drug safety information posted online.
So, what do we actually know about retatrutide?
Retatrutide fans say it helps you shred fat and gives you energy to build muscle. They invariably claim it’s better than Ozempic; fewer side effects, better results. They tout improved insulin sensitivity, nodding to the drug’s original purpose, which is to help control blood sugar for patients with type 2 diabetes.
There is some early evidence from clinical trials that at least some of this is true. Studies conducted on patients with obesity and diabetes suggest that retatrutide may be better at zeroing in on fat, preserving more lean muscle mass than earlier generations of injectable GLP-1 drugs like Ozempic and Mounjaro. Patients in the clinical trials, who all have diabetes and/or obesity, also had fewer complaints about nausea and diarrhea.
“What’s interesting about it is people don’t just lose weight and reach a plateau, they just keep losing weight,” Dr. Eric Topol, a cardiologist and leading longevity expert, told Business Insider after looking at Eli Lilly’s clinical trial results. “I joke that it goes skeletal because it’s so incredibly potent.” (Topol is not affiliated with Lilly’s clinical trials.)
We know less about research-lab ret.
The Brookings Institution, a research think tank, published a report in April on research labs selling counterfeit GLP-1s to Americans. It found just two European labs, with the bulk of peptide shipments pouring in from Chinese factories to distributors in the US. Business Insider could not independently verify how many research labs are producing reta and where they are based.
Exactly how those labs manufacture these copycat drugs is a bit of a mystery. The amino acid formula for retatrutide is easily searchable on the internet, but how easy is it to manufacture that chemistry? The Brookings report found that counterfeit versions of semaglutide are not perfect copies of what Novo Nordisk manufactures, which is more like a natural hormone. The copies are manufactured using “solid state” peptide synthesis, and some have had contaminants like formaldehyde left inside.
A whole cottage industry is springing up to test these research compounds. Serial investor Michael Carter, who has founded and run various gaming and software startups, recently started a company called Finrick, which he says is “creating the market force for these vendors to care about safety.” He said most of the retatrutide samples he has tested are the real deal, the “exact same thing” that Eli Lilly is making, but there’s really no way to be totally sure. However, Carter said the dosages are not always consistent from one batch to the next, even when they are labeled the same.
Doctors say that we need to learn more about the safety profile of these drugs and better understand the possible dangers for each patient, depending on their medical history. We saw with the first wave of GLP-1 drugs that some people had unpredictable reactions to Ozempic or Mounjaro, with life-altering side effects like stomach paralysis and sudden blindness.
There is, of course, a serious risk of contamination and bacterial infection when you’re getting powder from an online clinic that isn’t subject to regulations. Plus, there’s the contamination risk of mixing things up on your own, outside the clean rooms that pharma normally uses.
Reta fans know this. “I got burned with fake reta again,” is a common refrain in TikTok videos and Reddit forums. People pile in, offering names of labs they trust.
Business Insider reached out to some of the most popular labs cited on social media, but we didn’t receive a response.
“This is not kid stuff,” Topol said. “To be able to get this, if indeed that’s what it is — who knows what it really is.”
A tricky new world for physicians
At the popular testosterone and hormone clinic Gameday Men’s Health, chief medical officer Dr. Haleem Mohammed said he’s been seeing a consistent stream of guys coming in who are taking “ret.”
“Let’s toss that vial and wait until it’s gone through the trials and is available,” Mohammed told his Miami patients. “The risk profile, efficacy profile needs to be proven first before you start taking these.”
As someone who’s lost 70 pounds on the injectable weight loss drug tirzepatide, he said he’s sympathetic to the ambition and excitement these guys have for the field. He’s also frustrated by how quickly and easily they can get research chemicals online that don’t have the same safety checks that any pharmacy would require.
“Unless you’re a lab rat, or planning on being one, I wouldn’t recommend it,” Mohammed said. He’s seen issues with malnutrition in people taking these research peptides and electrolyte imbalances that could eventually lead to dangerous heart issues, if left unaddressed.
“You get a vial in the mail and you have no idea what’s in there and there’s no clinician involved whatsoever,” he said. “That’s what I’m educating against, constantly.”
Dr. Christle Guevarra, a licensed physician and powerlifter who works with bodybuilders and fitness enthusiasts at RP Strength, started hearing about retatrutide about six months ago. Some of her patients are open with her about taking reta and other gray market GLP-1 drugs. She said she discourages them from using retatrutide — she worries about contamination and all the unknowns that come with an unapproved drug — but tries to meet patients where they are to reduce harm.
“I can’t gate-keep people from going to find information,” Guevarra told Business Insider. “You have forums that are everywhere.” Some bodybuilders (controversially) take insulin, an anabolic hormone, in the hopes of building muscle and improving nutrient uptake in their muscles. Guevarra knows they’re going to do it, and she wants to do everything she can to help them understand the serious risks.
“I think it really is important now more than ever that we figure out a way to do a better job as physicians to check in on things like side effects, on things like muscle loss, on things like, ‘how are your lifestyle changes going?’ to make sure that our patients are safe,” Guevarra said.
The Ozempic boom exposed a gap between mainstream medicine and wellness culture
That retatrutide is booming before it’s even on the market underscores the huge demand for muscle preservation to go with weight loss.
Doctors have been raising concerns for years that, while GLP-1 drugs have myriad benefits, they trigger such rapid weight loss that it’s hard to preserve muscle or even have the energy to work out. That’s bad news for long-term health. You need muscle mass to protect your joints, stave off osteoporosis, and keep you energetic as you age. Less muscle can also, ironically, impact your metabolism, affecting digestion and making it harder to stay at a stable weight.
At least 10 biotech companies are racing to meet that need, developing therapies designed to preserve muscle mass in GLP-1 patients. Analysts project that muscle-preserving drugs could generate $30 billion by 2035.
In the meantime, there’s a gap, and a world of fitness influencers and online clinics flooding in to fill it, offering advice on how to build muscle.
Private wellness clinics offer pricey body composition scans to gauge a person’s muscle-fat ratio — far too costly for a physician to universally recommend and not deemed essential by insurance. Depending on your results, you may look for weight training or diet tweaks, or supplements. Back home, scrolling online, you may come across a buzzy new GLP-1 that costs $100 for a month’s supply, and supposedly preserves muscle while melting fat. People selling it on TikTok show you PDFs of test results ostensibly proving it is safe to use. You find hundreds of other social media creators who say it changed their lives. Would you try it?
Take Radovanic, who experienced incredible weight loss on a brand-name GLP-1, then lost insurance coverage for the drug as a result. He found solace and inspiration on TikTok, opening the door to a cheaper drug that he believes in.
Social media companies are trying to crack down. Earlier this week, TikTok banned the words “ret,” “reta,” and “retatrutide” from search, pointing to its community guidelines, which ban dangerous weight loss behaviors and marketing of weight loss products.
It wasn’t a huge problem for creators. They started posting about “redatrutide” instead, some mocking the censorship as “big pharma’s” latest intervention.
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