Retatrutide Is a New GLP-1 Hit. But Is It Legal?

You’ve heard of the popular glucagon-like peptide-1 (GLP-1) receptor agonist drug semaglutide (Ozempic, Wegovy) and GLP-1/GIP drug tirzepatide (Mounjaro, Zepbound). Now there’s a new kid on the weight loss block — or at least one that’s hanging around a dark weight loss alley.

Retatrutide is being hailed as a game changer for obesity by social media health influencers and those on weight loss forums, thanks to a handful of early clinical trials showing it could help users shed pounds faster than other drugs currently on the market. While it’s possible to purchase online without a prescription, retatrutide isn’t an FDA-approved medication. It hasn’t been thoroughly tested for safety or efficacy, which means this weight loss drug could put your health at risk.

The fact that retatrutide targets three different receptors may make it more effective than the current crop of weight loss therapies.

“Think of the glucagon receptor as a third tier,” says Sue DeCotiis, MD, a triple-board certified weight loss specialist and a clinical instructor at the NYU Grossman School of Medicine in New York City. “Working on that third receptor may provide added effects for appetite inhibition and insulin sensitivity.” In other words, it may help people lose more weight faster.

While retatrutide still has a ways to go in research before getting the green light from the FDA, online sources are already selling the drug. Does that mean it’s okay to buy it? The answer is complicated.

A review of online sources suggests that suppliers aren’t transparent about this rule. Some highlight retatrutide’s rapid weight loss benefits while dancing around the fact that the medication hasn’t been FDA approved, referring to it as an “investigational drug” or one that’s “still undergoing clinical research.” Those that do mention the lack of FDA approval tend to do so in tiny print at the bottom of a product page. Some suggest vaguely that some kind of medical evaluation will take place or that buyers must sign a release.

Other storefronts avoid health claims while stating that their retatrutide is intended for research purposes. “They get around [the FDA’s restrictions] by saying the product is for lab use, or not for human or veterinary use,” says Dr. DeCotiis. But there’s usually nothing stopping the average person from buying these products, either. “It’s a little bit shady,” she says.

There isn’t enough information to determine whether retatrutide is safe. The medication hasn’t completed the clinical drug trial process yet and thus isn’t approved by the FDA. Those unknown risks could be even greater when purchasing “retatrutide” from an illicit source, because it hasn’t been regulated or evaluated by health authorities, says DeCotiis.

These risks may not be deal breakers for most people, and it’s very likely that retatrutide will be approved by the FDA within the next few years, says DeCotiis. But it’s important to have a clear understanding of the drug’s risks before it can be safely prescribed. “We need to better understand how the dosing and dose intervals affect all of the above risks and results,” says Snyder.

Experts also warn that buying compounded retatrutide from an online pharmacy that isn’t supposed to be selling it in the first place could be dangerous. “If you’re buying a drug through illegitimate channels, you may run into quality control issues,” says DeCotiis.

What’s more, since you’re getting it without a prescription, “there’s no medical oversight if you develop complications like severe GI effects, pancreatitis, gallbladder issues, dehydration, or dangerous drug interactions,” says Snyder. “You assume medical, quality, and legal risks without any of the safeguards that are built into regulated care.”

Weight loss medications should be taken under the supervision of a healthcare provider, which isn’t available when you purchase retatrutide online without a prescription. “You need to be monitored,” says DeCotiis.

Retatrutide’s purported results may be tempting, but experts agree that you should not purchase or use the drug now. If you’re interested in trying a weight loss medication, make an appointment with your doctor to discuss FDA-approved options like semaglutide or tirzepatide.

"I strongly advise patients to stick with FDA-approved, properly regulated prescription medications prescribed through licensed medical providers,” says Snyder. “That’s the only way to ensure you’re receiving a real drug at the right dose under appropriate medical supervision.”

• Retatrutide is an experimental triple-receptor agonist drug that has shown promising weight loss results in preliminary clinical trials.
• The drug is not yet approved by the FDA and is still undergoing a phase 3 clinical trial, which is expected to conclude in 2026.
• Despite the lack of approval, some online storefronts are purportedly selling retatrutide online, sometimes claiming that the substance is “for research purposes only.”
• Experts strongly caution against buying any form of retatrutide, as the entire market is unregulated, and even the legitimate compound has not yet been studied sufficiently to know that it is safe.