Doctors have long known that people with type 2 diabetes usually lose less weight on obesity drugs than everyone else. The new Lilly weight-loss drug retatrutide diabetes results are in, and in the latest Phase III trial the weekly shot did not follow that script.
The study is called TRIUMPH-2. It tested Eli Lilly’s once-weekly retatrutide, a triple agonist that hits the GLP-1, GIP and glucagon receptors at once (three targets, one shot). According to a Medical Xpress write-up, 1,152 adults with obesity and type 2 diabetes got weekly injections for 80 weeks.
How much weight did people lose in the retatrutide diabetes trial?
At the top 12 mg dose, the average loss was 18.8% of body weight. That is about 45 pounds, nearly three bowling balls, versus 5.1% for placebo. Inside Precision Medicine reports the lower doses did less, but still a lot. The 4 mg dose produced 11.9%, and the 9 mg dose produced 16.8%.
Nearly half of the people on the top dose lost at least 20% of their body weight. Almost a third lost at least 25%.
That is territory that used to belong to bariatric surgery.
Now, a fair warning on the numbers. Lilly’s own July topline release put the 80-week figure at up to 20.8%. Other outlets, including The Pharmaceutical Journal, repeated that number. The gap probably comes down to how the trial results are counted. The published paper is the place to settle it. Either way, the story is the same: this is big.
Blood sugar results from the triple agonist diabetes drug
Weight is only half the point for people with diabetes. Blood sugar control is the other half. According to Inside Precision Medicine, HbA1c fell by as much as 1.5 percentage points. And 63% of participants hit both an HbA1c of 6.5% or lower and at least 10% weight loss.
Waist size, blood pressure, cholesterol and a key inflammation marker also improved. In other words, the drug moved a whole cluster of numbers that doctors worry about, not just the scale. Blood sugar is a hot topic right now, as a sweet-protein study on blood sugar spikes showed in a very different way.
What retatrutide diabetes results mean for patients
Here’s the thing: if you or someone in your family has type 2 diabetes, this is the headline to watch. Lilly says it plans to submit an application to the FDA in the first quarter of 2027. Approval is not guaranteed, and the drug is still investigational. Nobody can legally prescribe it today.
Two more caveats. TRIUMPH-2 was not a head-to-head race against Zepbound, so any comparison with older drugs is a rough guess. And this write-up does not cover side effects. Nausea and other stomach trouble are the usual price of this drug class. The safety data in the full paper deserves a close read, especially after a suspected vision-loss case tied to Wegovy-type drugs raised new questions about this whole family of medicines.
This is also not a surprise out of nowhere. Lilly has now posted three big retatrutide readouts this year. They include a separate diabetes trial in March and an obesity trial in May that showed even larger losses. The results in the diabetes group were the missing piece. Investors are watching too, and Lilly’s earnings were in focus on a packed market day.
The next question is the one every patient will ask. If the FDA says yes, who gets it, and what will it cost?
