- Retatrutide led to 28% body weight loss over 80 weeks, similar to bariatric surgery.
- The experimental drug has shown improvements in cardiometabolic health alongside weight reduction measures.
- Retatrutide is currently not available for market and awaits FDA approval in 2027.
In the battle of the bulge, scales may soon tip in favor of Eli Lilly’s newest contender, an experimental drug called retatrutide. The company said Thursday that those taking the injection in a clinical trial shed more pounds than those on any of the recent popular weight-loss drugs were able to lose.
As The New York Times reported, “Among the heaviest patients in the trial, the results were on par with those seen with gastric bypass surgery, the only effective treatment for most with severe obesity.”
The results were announced in a news release this week and have not been peer reviewed or otherwise published yet. But the company said the goal is to help very heavy patients who need to lose a lot of weight.
Per Eli Lilly, 45.3% of those receiving the 12 mg dose of the medication lost 30% or more of their weight, “a level long associated with bariatric surgery.” At a lower dose, 4 mg, participants with a body mass index of 35 and above lost 47.2 pounds or 19% of their body weight at 80 weeks, on average.
A BMI of 30 or above is considered obese. Overweight is 25 and above.
Other benefits
“Obesity is a chronic disease, and people living with obesity deserve treatment options that match the complex biology of their neurometabolic disease,” said Dr. Ania Jastreboff, professor of medicine and pediatric endocrinology at the Yale School of Medicine, as well as director of the Yale Obesity Research Center and the clinical trial’s lead investigator.
Added Jastreboff in a written statement, “It was impressive to see that every dose of retatrutide resulted in clinically meaningful weight reduction for nearly all participants, and people with severe obesity on the highest dose lost on average 30% of their body weight over two years. Importantly, treatment with retatrutide not only resulted in robust weight reduction, but also in clear improvements in assessed cardiometabolic health measures. For patients I see in clinic, retatrutide may potentially be a highly impactful future tool to treat their obesity and transform their health trajectory.”
The drug might also be helpful with other conditions, including heart disease.
It’s important to note the drug is not on the market yet, and the company expects to seek approval from the U.S. Food and Drug Administration in 2027. So if one sees the drug marketed outside of a clinical trial, it’s not the real thing.
Per the Times, “As word has spread about promising results in Eli Lilly’s clinical trials, some Americans have been going online to order knockoff versions from China — alarming physicians and researchers, who are concerned that patients are not being monitored and could be harmed."
What studies show about weight-loss drugs
In a release in December, the company noted that the weight loss, which at that point averaged 71.2 pounds, was significant enough that some in the phase 3 clinical trial worried they were losing too much weight. It noted, too, that osteoarthritic pain was substantially reduced.
Two wildly popular weight-loss drugs, Eli Lilly’s Zepbound and Novo Nordisk’s Wegovy, have allowed people to lose about 20% of their body weight. The pill versions result in somewhat less weight loss, but have other advantages, such as not requiring shots for those who hate needles.
Retatrutide is given as a weekly injection, the dose increasing gradually to minimize the gastrointestinal effects that have also marked the other weight-loss injections.
The Times added that Eliy Lilly is the first pharmaceutical company to be valued at $1 trillion. But it’s also locked in a dispute with the FDA, which it sued in 2024. The FDA has classified retatrutide as a “traditional drug, not as a biologic drug. The fight, which remains tied up in court, hinges on a highly technical dispute over how many amino acids retatrutide has in its chemical structure.”
That matters to Eli Lilly, because if it’s classified as a biologic, that will let the company charge higher prices for more years and prevent other companies from making versions of it.