A shadowy market for weight-loss drugs has emerged online

In late 2022, pharmacist Joseph Lambson got an unusual call from a poison control specialist.

He said, “Hey Joe, I’m getting these weird calls about semaglutide.” According to the specialist’s calculations, people were giving themselves 10 times the correct dose. But that didn’t make sense. The drug is the key ingredient in the blockbuster diabetes and weight-loss medications Ozempic and Wegovy. Both come in prefilled injector pens, which typically take the guesswork out of dosing.

Lambson, a board-certified toxicologist, knew right away what was going on. “This drug is probably being compounded,” he remembers thinking. He was right. After investigating, Lambson’s team at the Utah Poison Control Center in Salt Lake City reported that people were overdosing on compounded semaglutide. That means “a lot of nausea, a lot of vomiting, a lot of diarrhea,” he says.

Ozempic and Wegovy, made by Novo Nordisk, had both been on the U.S. Food and Drug Administration’s drug shortage list since 2022. Across the boundless wilds of the internet, online sellers sprang up to meet demand. Some sold compounded medications. When pharmaceutical companies can’t keep up with demand for their FDA-approved drugs, compounding pharmacies can step in to fill the gap. These pharmacies measure and mix a drug’s active ingredient, creating a product that’s essentially a copy of the brand-name drug. Outside of shortages, compounding pharmacies routinely provide medicines that aren’t otherwise available or need to be tailored to a particular patient.

But even with legal, compounded forms of semaglutide, which require a prescription and usually come premixed in a vial with a syringe, patients can run into trouble, as Lambson found. People weren’t always sure how to take the drugs, so “they just went for it,” he says.

Last year in Clinical Toxicology, emergency medicine doctors reported similar issues in a few cases. One man injected 20 times the correct dose of semaglutide because he misunderstood instructions.

Semaglutide belongs to a class of medications known as GLP-1 receptor agonists. Even when used correctly under doctor supervision, they come with potential side effects. And when patients have to pull up the correct dose with a syringe, the risks go up. Soon, the situation could get even dicier.

In February, the FDA removed semaglutide from the drug shortage list. By May, pharmacies will no longer be able to dispense compounded versions, though that depends on ongoing litigation. It’s a similar story with another GLP-1 drug, tirzepatide, the main ingredient in Mounjaro and Zepbound, Eli Lilly’s diabetes and weight-loss drugs. The FDA erased tirzepatide from the drug shortage list in October.

But just because a drug is off the list doesn’t mean supply is guaranteed. And even with new discounts offered by pharmaceutical companies, the drugs’ prices keep them out of reach for many patients — especially since insurance won’t always cover them.

High prices could drive people to seek out more affordable versions from less-than-reputable sources. “That’s what I’m worried about,” says C. Michael White, a pharmacist and researcher at the University of Connecticut in Storrs. People reliant on legitimate compounded products may soon “go further down the rabbit hole.”

That rabbit hole includes websites that sell GLP-1 drugs “for research only,” like powdered semaglutide or tirzepatide that’s intended for use in the lab, not for humans. With just a few clicks, anyone with an internet connection can purchase a vial of the drugs for about a hundred bucks — and without a prescription. Consumers don’t need to verify they’re a researcher or offer proof that they belong to a scientific institution. All they need is a credit card.

“I feel healthier now than I felt when I was in my 40s.”

Melanie T.
tirzepatide user

Scientists around the country have raised concerns about drug quality, dosing and scams. Buyers must rely on themselves to reconstitute and inject these drugs, without physician guidance. That means buying a specific type of sterile water, calculating how much to add to the vial of freeze-dried powder, mixing it and then figuring out exactly how much to draw up in a syringe and inject into the body. It’s a recipe for confusion — and potentially danger.

But for many people, the benefits of GLP-1 drugs are well worth the risks. They can be a lifeline, helping people lose weight, lower the risk of heart attack and improve their all-around quality of life. For Melanie T., a 70-year-old woman on compounded tirzepatide, the drug has transformed her body and her life. “I feel so good now,” says Melanie, who is using only her first name to protect her privacy. “I feel healthier now than I felt when I was in my 40s.”

When her compounding pharmacy stops dispensing tirzepatide, she’s open to exploring her options. “What is my alternative if I don’t have this?” she says. “I don’t really have one.”

The life-changing effects of GLP-1 drugs

Melanie injected her first dose of compounded tirzepatide into her abdomen on August 8, 2024.

She had always been petite, 5 feet, 3 inches tall, and between 115 and 120 pounds, but “menopause changes everything,” she says. At 70 years old, she weighed 174 pounds and felt terrible. Her knees hurt, her back hurt, she was short of breath, and she had a laundry list of other health issues, including hypothyroidism, fibromyalgia and swelling in her legs.

For years, Melanie went from doctor to doctor, trying all sorts of therapies and diets. There were supplements, IV drips of vitamin C, intermittent fasting (when she ate only during certain times of the day) and water fasting (when she consumed only water and electrolytes for days at a time). Nothing seemed to help. She was sick and not getting better, Melanie says. “The weight was not going down.”

Finally, she says, “I said the hell with this.” Her daughter told her about GLP-1 drugs, and Melanie ordered compounded tirzepatide from an online telehealth company. That involved completing an online intake form and video chatting with a doctor, who prescribed the medication.

GLP-1 drugs imitate an assortment of gut hormones involved in metabolism and act on the body in myriad ways; they can cause food to stick around in the stomach longer, lower blood sugar and tell our brains that we’re not hungry. Semaglutide mimics one hormone, GLP-1. Tirzepatide mimics two, GLP-1 and GIP. And retatrutide, still in clinical trials, mimics those two plus an additional hormone called glucagon. Generally, more hormones mimicked means more weight lost.

After Melanie’s first week on tirzepatide, she lost five pounds. By week two, she had dropped nine. When I talk to Melanie in March, she has gone down to 116 pounds. Her joint pain has disappeared, as has her fibromyalgia. But one of the biggest changes has been her relationship with food. Ice cream, once a favorite treat, is now “so overpoweringly sweet that it’s disgusting,” Melanie says. Food overall is just not as enjoyable. “I eat because my brain tells me I need to eat. I don’t eat for cravings.”

“I eat because my brain tells me I need to eat. I don’t eat for cravings.”

Melanie T.

That silencing of food noise, the relentless buzz of food-related thoughts in the brain, is a common effect of GLP-1 drugs. So are Melanie’s weight-loss results. On average, people on a high dose of tirzepatide lose about 20 percent of their body weight. With such drastic results, it’s not surprising that some 6 percent of U.S. adults may be on a GLP-1 medication, according to a 2024 poll.

As Melanie discovered, GLP-1 drugs can help the body in other ways, too. A study of nearly 216,000 U.S. veterans found that people on the drugs were less likely to have substance use disorders, psychotic disorders, seizures, dementia and infections, among other health benefits, researchers reported in January in Nature Medicine.

But the medications aren’t without side effects. The study uncovered the usual gastrointestinal issues linked to GLP-1 drugs, like abdominal pain, nausea and vomiting, as well as less well-known conditions, including stomach paralysis and diverticulitis, where bulging pouches of the large intestine become inflamed. Such side effects may help explain why 65 percent of people without type 2 diabetes who take a GLP-1 drug quit within a year, scientists suggested in January in JAMA Network Open. Serious problems are likely to be rare, though. Less than four emergency department visits occur for every 1,000 patients dispensed semaglutide, researchers estimated in April in the Annals of Internal Medicine.

For Melanie, the first two weeks on tirzepatide were the roughest. She had no appetite and severe nausea. “It felt like somebody donkey-kicked my stomach,” she says. “I thought I was going to die.” She stayed inside, laid on the couch and rode it out. By the third week, most of the side effects had disappeared.

Today, Melanie’s got a compounded product she trusts — and can afford — and feels comfortable using a syringe and vial. But recent data suggest that not everyone is so adept.

Off-brand drugs can lead to dosing errors

In New Mexico, where Lambson is now the director of the state’s Poison and Drug Information Center, GLP-1–related calls have doubled every year since 2021. That trend holds up nationally. In 2024, poison control centers across the United States managed 8,502 GLP-1–related cases, says Kaitlyn Brown, clinical managing director of America’s Poison Centers, a national nonprofit organization that represents the 54 accredited poison centers in the United States. That’s compared with 892 cases logged in 2019 — an 850 percent increase.

It’s impossible to say how many of these cases stem from compounded or other versions of the drugs. But about 75 percent were due to unintentional therapeutic errors, meaning people used the wrong dose or otherwise administered the drug incorrectly. From a poison control perspective, Brown says, “it’s obviously more of a risk when you’re giving a patient a syringe and a vial.”

As of February 28, the FDA has received nearly 800 reports of adverse events linked to compounded semaglutide or tirzepatide. These reports aren’t proof of causation, but it’s possible some adverse events may be due to dosing errors. And dosing is just part of the confusion. Vendors selling compounded GLP-1 drugs sometimes have incomplete or misleading information on their websites, researchers reported in January. A Super Bowl commercial spotlighted these issues in February, when two U.S. senators sent a letter to the FDA raising concerns over a telehealth company’s ad about compounded weight-loss medications. The ad made no mention of risks or side effects.

“Everyone’s trying to make money — manufacturers, compounding pharmacies, counterfeiters, everybody,” says Tim Mackey, a public health researcher at the University of California, San Diego. “I really think the patient is the victim here.”

That’s where responsibility for vetting online vendors and pharmacies tends to fall. Patients can check if a compounding pharmacy in their state is legitimate and licensed, says pharmacist Tenille Davis, chief advocacy officer at the Alliance for Pharmacy Compounding. That industry trade organization has developed an online tool for this task and has suggested questions consumers can ask when choosing a compounding pharmacy.

Compounded drugs, though legal, are not FDA-approved. According to the agency, it doesn’t “review compounded drugs for safety, effectiveness or quality before they are marketed.” That doesn’t make them inherently dangerous, Davis says. “Compounding is a part of the practice of pharmacy,” she says. “Pharmacists jump in and help with drug shortages all the time.” But never like what’s happened with GLP-1 drugs.

Even though Ozempic, Mounjaro and Wegovy are off the shortages list, pharmacies have reported difficulty obtaining enough of these drugs to meet demand, Davis says. Without compounded versions to shore up supply, “we worry that patients are going to have access issues with this medication.”

That could push patients from the sometimes-complicated world of compounded drugs into far-less-certain territory. With brand-name GLP-1 drugs either out of supply or too expensive for some patients to afford, more people may seek out the shadowy universe of GLP-1 peptides. These chemicals include the same active ingredient as the brand-name drugs and compounded versions, but don’t require a prescription. That’s because vendors say these peptides are for research use only or not for human consumption.

And with neither physician nor pharmacist for support, people are hunting for medical advice on these peptides in unconventional places, like private Facebook groups and secret social media chats — where drugs are given code names and users test unapproved chemicals on themselves.

A community of peptide users

As part of my reporting for this story, I joined multiple peptide groups online. I was kicked out of the first one I got into on Facebook. It’s a private group with more than 22,000 members, and the rules stipulate that any talk of research peptides for human use is not allowed.

But group members exchange advice on where to buy peptides and how to administer them. Some people refer to them as S$ma or T!rz and say they’re for an “RS,” or “research subject,” a way to avoid calling attention to human use. Others are more direct, recommending peptides for weight loss and describing their experiences using them.

These include the usual suspects, like semaglutide and tirzepatide, but also retatrutide, the GLP-1 drug still being tested in clinical trials. It might help patients shed more weight than anything currently on the market. “I just started Reta last week,” one member posted. “Felt better than when I was taking sema.”

When I identified myself as a writer for Science News and asked if anyone would speak about their experiences, people called me a snitch, a cop and a Big Pharma shill. One member suggested that this story could shut down peptide-seller websites. “Don’t ruin what we have,” another said. The concerns underscore just how difficult it can be to access medications like Wegovy and Zepbound — and how important they are to people’s lives.

Despite the benefits, people may face negative attitudes about using drugs for weight loss. They may be “stigmatized for taking the ‘easy way out,’ ” A. Janet Tomiyama, a UCLA psychologist, wrote in the January Annals of Behavioral Medicine.

That’s not how we should treat people who want to go on these medications, says Kai Jones, an endocrinologist at Washington University in St. Louis. In her practice, she and her colleagues talk with patients about stigma, weight and how obesity requires chronic management. “Often, folks are blamed because of the way they look or their body composition,” she says. “I think it’s important to reach out to folks with empathy, to understand where they’re coming from.” That includes figuring out what barriers people face when trying to access these medications.

Name-brand drugs come with big price tags

GLP-1 drugs are big business. In February, Novo Nordisk reported a 25 percent jump in sales from 2023 to 2024, largely thanks to Ozempic and Wegovy. Eli Lilly’s revenue rose 32 percent, driven by sales of Mounjaro and Zepbound.

Though many insurance plans pay for the meds for type 2 diabetes, coverage can be spotty for people who are overweight or obese but do not have diabetes. That’s why Melanie’s insurance didn’t cover a GLP-1 prescription. For her, paying out-of-pocket was out of the question. And because people may remain on the meds indefinitely, costs can pile up.

The list price for GLP-1 drugs runs from around $1,000 to $1,300 per month. To expand access, pharmaceutical companies have begun offering discounts. Eli Lilly now sells Zepbound, its tirzepatide obesity drug, directly to consumers for $349 or $499 per month, depending on the dose. But the deal is cash only, and the medication comes in a single-dose vial, not an injector pen. That’s still too high of a price for Melanie — double what she’s currently paying for compounded tirzepatide.

In March, Novo Nordisk announced a similar plan for Wegovy. Cash-paying customers can buy injector pens for $499 per month.

Even with new discounts, though, purchasing peptides from “research only” sellers may still be the cheapest option. A one-month supply can cost less than $100.

Lambson says he understands the frustration of consumers who can’t afford or don’t have access to either brand-name or compounded versions of GLP-1 medications. But he worries about people tracking down their own peptide supply. Going online and buying the drugs from unvetted sources that don’t require a prescription “can really put you at harm’s risk,” he says.

Why experts are worried about peptide sellers

Last year, Mackey, the public health researcher at UC San Diego, and colleagues reported purchasing semaglutide from six online vendors that didn’t require a prescription. “We got scammed on three of the six orders,” Mackey says. Vendors would fake tracking numbers that showed packages held up at customs and then demand hundreds of dollars in fees to release the medication.

Of the three orders that did arrive, one had high levels of endotoxin, a sign of contamination. All three orders had low purity levels; in one case, just 7.7 percent purity, compared with the 99 percent purity claimed by the seller, Mackey’s team reported last year in the Journal of Medical Internet Research. “Such a low purity is concerning,” Mackey says, “because you have no idea what the rest is and whether it could be harmful when injected.”

And though the semaglutide peptide sellers included “research use only” on their labels, one seller offered injection guidance, and others touted the potential health and weight-loss benefits of their products. “It’s clear that they’re advertising for human use, but they’re trying to skirt the rules,” Mackey says.

Websites like the ones Mackey ordered from aren’t hard to find — anything but. “Once you start looking, they find you,” says White, the University of Connecticut pharmacist. Just Googling how to buy these drugs without a prescription brought up ads on his and his colleagues’ Facebook and Instagram feeds.

Of 38 websites that sold GLP-1 drugs “for research purposes,” only four asked buyers to check a box stating that they were a researcher, White’s team reported in the Annals of Pharmacotherapy last September. And none of the 38 sites verified that buyers were actual researchers. Some of the companies White and colleagues investigated display customer testimonials on their websites or social media ads trumpeting how well the products work for weight management or suggesting they could be used by humans for non-research purposes.

Selling these drugs under the guise of research is a huge loophole “that the FDA really needs to fill,” White says.

The FDA has already issued warning letters to several online vendors. After a December warning to Summit Research Peptides, the company still sells tirzepatide and semaglutide peptides but no longer includes health claims on its website. And US Chem Labs, which the FDA warned in February 2024, removed language from its website extolling their products’ weight-loss powers, though its product pages for semaglutide still include information about therapeutic uses.

For Melanie, buying from peptide-selling websites like these seems like a workable option. She’s not worried about measuring out the water or mixing the drug. Though she’s not at that point, yet. Her current supply of compounded tirzepatide will take her almost to September. She’s stretching the time between doses, injecting herself every week and a half or so. Melanie has considered going off the meds completely, but she’s not sure how her body would respond.

Melanie is not flippant about where her drugs come from, nor is she careless with her medical decisions. She’s a thoughtful person who takes her health seriously. It’s just that, for her, the risk of not having tirzepatide is greater than the risk of buying it from an unvetted source.

“I can’t go back to feeling the way I was feeling for all those decades — because I got a taste of feeling healthy now,” she says. “I can’t go back.”