• Eli Lilly is developing a more potent weight-loss drug called retatrutide.
• In the first head-to-head trial versus Ozempic, retatrutide takers lost roughly twice as much weight.
• Retatrutide is not FDA-approved yet, but some peptide sellers are skirting the law.

Gym bros call it "reta." Eli Lilly is calling it the winner.

On Wednesday, the pharmaceutical giant announced the results of the first clinical trial pitting Ozempic against its newest, most powerful, and yet-to-be-approved next-generation injectable medication for obesity and diabetes: retatrutide.

Retatrutide won — and it wasn't even close. Type 2 diabetes patients on the highest dose of Ozempic (2 mg) lost an average of 21 pounds over a period of about a year and a half on the drug. Those on retatrutide lost an average of 44 pounds (9 mg) to 47 pounds (12 mg) during that same time. Patients also saw steeper reductions in their A1C, a key marker of blood sugar control (2.2% vs 1.8%).

"We believe retatrutide, if approved, could shift the treatment paradigm for people living with type 2 diabetes, obesity and related cardiometabolic conditions," Eli Lilly's Kenneth Custer, the president of Lilly Cardiometabolic, said in a release.

They're calling it 'King Kong'

Ozempic (from Novo Nordisk) was the very first medication of its kind — a novel peptide that mimics one gut hormone, called GLP-1.

Several years later, Mounjaro (from Eli Lilly) was approved, mimicking two hormones, GLP-1 and GIP, and delivering stronger results.

Insiders are calling Eli Lilly's retatrutide the "triple G" or "King Kong" for weight loss because it mimics three hormones: GLP-1, GIP, and a third peptide hormone called glucagon, which helps break down stored fat into energy. Some say it could rival bariatric surgery in clinical results in terms of weight loss.

Eli Lilly is expected to submit retatrutide to the US Food and Drug Administration for approval in early 2027. If all goes well, it could be available sometime next year, for conditions including obesity, obesity-related sleep apnea, and knee osteoarthritis.

In this clinical trial, side effect profiles were generally similar between patients taking Ozempic and retatrutide, but slightly more patients on retatrutide reported diarrhea, while constipation was slightly more common among Ozempic-takers. People on retatrutide also had slightly higher rates of a rare side effect called dysesthesia, triggering tingling, skin-on-fire type sensations.

The clinical trial results have not yet been peer-reviewed or published in a medical journal, but were released as the company prepares to announce its quarterly earnings on Thursday.

Knock-off reta is already booming on the black market

The drug, which is still in clinical trials, has attracted copycat peptide sellers shipping powders labeled "reta" from overseas, stoking a gray market of do-it-yourself injections. Bodybuilders say it helps shred fat and reduce appetite, with fewer side effects than other injectable weight-loss pens.

But nobody really knows exactly what they are taking, though their results seem to roughly mirror what happens when people take the real thing in clinical trials.

In an unusual move, Eli Lilly addressed the pre-approval black-market hype in their release announcing the latest results.

"Retatrutide is an investigational molecule that has not been approved by FDA or any regulatory organization anywhere in the world," the company said in a statement. "Anyone purporting to sell retatrutide to consumers is breaking the law."