Eli Lilly says retatrutide produces more than double the weight loss seen with Ozempic

• Eli Lilly is working on a stronger weight-loss medicine called retatrutide.

• In the first direct comparison with Ozempic, people taking retatrutide lost about twice as much weight.

• Retatrutide has not been approved by the FDA, but some peptide sellers are already operating outside the law.

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

The pharmaceutical company has disclosed results from the first clinical trial to compare Ozempic with its newest and most powerful next-generation injectable for obesity and diabetes, retatrutide.

The new drug came out far ahead. In the study, people with type 2 diabetes taking the highest dose of Ozempic, 2 mg, lost an average of 21 pounds over roughly a year and a half. Those on retatrutide lost an average of 44 pounds at the 9 mg dose and 47 pounds at the 12 mg dose over the same period. Patients on retatrutide also saw a bigger drop in A1C, a key measure of blood sugar control, with results of 2.2% versus 1.8%.

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

Some are calling it “King Kong”

Ozempic, made by Novo Nordisk, was the first medicine of its kind: a peptide that mimics the gut hormone GLP-1.

Years later, Eli Lilly introduced Mounjaro, which mimics two hormones, GLP-1 and GIP, and produced even stronger results.

Retatrutide is drawing attention as a “triple G” or “King Kong” drug because it targets three hormones: GLP-1, GIP, and glucagon, the latter helping the body break down stored fat for energy. Some observers say its clinical results could put it in the same range as bariatric surgery for weight loss.

Eli Lilly expects to submit retatrutide to the U.S. Food and Drug Administration for approval in early 2027. If the process goes smoothly, the drug could become available sometime next year for conditions including obesity, obesity-related sleep apnea, and knee osteoarthritis.

In the trial, side effects were broadly similar between the two drugs. However, diarrhea was reported slightly more often among retatrutide users, while constipation appeared slightly more often among Ozempic users. Retatrutide was also linked to somewhat higher rates of dysesthesia, a rare side effect that can cause tingling or a burning sensation in the skin.

The findings have not yet been peer-reviewed or published in a medical journal. The company released them as it prepared to report quarterly earnings.

Copycat retatrutide is already spreading on the black market

Although the drug is still in clinical trials, it has already inspired copycat peptide sellers to ship powders labeled “reta” from overseas, fueling a gray market for do-it-yourself injections. Bodybuilders say the substance helps reduce appetite and burn fat, with fewer side effects than other injectable weight-loss pens.

Still, there is no reliable way to know exactly what buyers are getting, even if their reported results seem to resemble those seen in clinical trials of the real drug.

In an unusual step, Eli Lilly addressed the pre-approval black-market attention in its announcement of the latest trial results.

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