Retatrutide, a Superpowerful Obesity Drug, Is Not Yet FDA-Approved — but Knockoffs Abound

GLP-1 drugs such as semaglutide (Wegovy, Ozempic), tirzepatide (Zepbound, Mounjaro), and orforglipron (Foundayo) have become wildly popular because they can help people lose a substantial amount of weight.

Soon there could be a new option, retatrutide (nicknamed “reta” and “Godzilla”), that promises unprecedented weight loss — but it’s not ready for prime time quite yet.

In the meantime Lilly has agreed to provide early access to the drug for a limited number of patients with severe obesity through its “compassionate use” program.

The ability to target three different receptors may explain why retatrutide is 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.”

Phase 3 trials also confirmed that retatrutide may have special benefits for people with obesity who also have diabetes or heart disease. Participants with obesity and type 2 diabetes on the highest dose (12 mg) lost nearly 21 percent of their starting weight over the 80-week trial, which is significant because people with type 2 diabetes typically lose less weight on obesity medications than people who don’t have type 2 diabetes.

For people procuring retatrutide directly from Eli Lilly under its compassionate-use program or taking part in a registered clinical trial, the medication is legal. But the copycat medication sold to the general public through online purveyors and some med spas and wellness clinics is illegal.

“Retatrutide cannot be legally prescribed or dispensed outside of authorized clinical trials,” says Michael Snyder, MD, the medical director of bariatric surgery at HCA HealthONE Rose in Denver and an in-house obesity specialist at FuturHealth. “Since there is no FDA-approved retatrutide product, pharmacies and compounders cannot legally compound it.”

A review of online sources suggests that retatrutide vendors are largely ignoring the law. Some highlight retatrutide’s rapid weight loss benefits while dancing around the fact that the medication hasn’t been FDA approved. They may refer to it as an “investigational drug” or one that’s “still undergoing clinical research.” Those that mention the lack of FDA approval tend to do so in tiny print at the bottom of a product page. Or they might suggest that some kind of medical evaluation will take place, or that buyers must sign a release.

Other purveyors operating outside legitimate channels avoid making any health claims. “They attempt to skirt 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. “It’s a little bit shady,” she says.

When suppliers operate in legal gray areas like this, it seems unclear if the act of purchasing retatrutide is illegal. Retatrutide isn’t a banned drug, and “the substance itself isn’t necessarily illegal,” says Tenille Davis, PharmD, the chief advocacy officer at the Alliance for Pharmacy Compounding.

But experts have no confidence that bootleg retatrutide purchased on the gray market is in fact retatrutide — or that it is safe to use.

“Gray market” retatrutide poses serious health risks, experts say, while legitimate retatrutide under clinical investigation appears to be generally safe.

Bootleg Retatrutide Poses Serious Health Risks

Experts warn that buying retatrutide from a vendor that isn’t legally permitted to sell it could be dangerous. “If you’re buying a drug through illegitimate channels, you may run into quality control issues,” says DeCotiis. A contaminated product could be harmful.

“There’s no guarantee that what the retailer says the drug contains is actually in it,” says Davis.

What’s more, since you’re getting this medication 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 Dr. 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 from the gray market. “You need to be monitored,” says DeCotiis.

Legitimate Retatrutide Is Generally Safe, Studies Show

Late-stage clinical research studies have shown that the retatrutide manufactured by Eli Lilly is generally safe.

Additionally, about 11 percent of study participants on the highest dose discontinued the medication because of side effects. A number dropped out because they thought they were losing too much weight.

Some experts are also worried about the possible effects of retatrutide’s very rapid and dramatic weight loss.

“There’s a concern that there may be a greater likelihood of bone fractures,” says Snyder.

These risks may not be deal breakers for people with severe obesity, for whom the benefits of retatrutide may outweigh the risks. Experts emphasize the importance of ongoing communication with a healthcare provider who can prescribe medication and doses depending on a person’s individual needs.

Research studies underway may also help shed more light on best practices for prescribing retatrutide. “We need to better understand how the dosing and dose intervals affect all of the above risks and results,” says Snyder.

The promise of super-powered weight loss from retatrutide may tempt you to seek out illegal versions, but experts agree that you should avoid them. If and when the medication receives FDA approval, talk with a healthcare provider to decide if it is the best option for you.

In the meantime, if you have obesity and feel like a GLP-1 drug could help, make an appointment with a physician to discuss existing FDA-approved options.

“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.”

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