Eli Lilly said on Wednesday that its experimental weight-loss shot, retatrutide, beat Novo Nordisk’s Ozempic in the first trial to test the two drugs against each other1. In adults with type 2 diabetes, people on retatrutide lost more than twice as much weight as people on Ozempic, and their blood sugar fell further, according to the company2. The results have not yet been peer reviewed or published in a medical journal1.
What Lilly reported
The trial was a Phase 3 study, the last big stage of testing before a company asks for approval. It included more than 1,000 adults with type 2 diabetes2. It compared two doses of retatrutide, 9 mg and 12 mg, with a 2 mg dose of Ozempic3, which is Ozempic’s highest approved dose2. All the drugs are given as a shot once a week2.
After 80 weeks, about a year and a half, Lilly reported these average results2:
- Retatrutide 12 mg: 47.4 pounds lost2
- Retatrutide 9 mg: 44.3 pounds lost2
- Ozempic 2 mg: 20.9 pounds lost2
The trial also tracked A1C, a blood test that shows average blood sugar over the past few months. Both retatrutide doses lowered A1C by an average of 2.2 percentage points3. For Ozempic, Business Insider, Geo News and SSBCrack News reported a drop of 1.8 points124, while The News International reported 1.5 points3. The full data should settle which figure is correct.
Lilly also said retatrutide led to greater improvements in some heart risk factors, including cholesterol and blood pressure2.
“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 Health, said in the company’s release1.
How the drug is meant to work
Ozempic was the first drug of its kind. It copies one gut hormone, GLP-1, which reduces appetite and slows digestion1. Lilly’s Mounjaro came later and copies two hormones, GLP-1 and GIP1. Retatrutide is designed to act on three: GLP-1, GIP and glucagon, a hormone that helps break down stored fat into energy1. That is why some people call it “triple G”2.
Earlier trials of retatrutide were run against a placebo (a dummy shot), not against another drug. In one large trial of 2,339 adults with obesity but without diabetes, people on the 12 mg dose lost an average of 28.3% of their body weight over 80 weeks, compared with 2.2% on placebo, according to Lilly’s figures as summarized by RetaRadar5. People with diabetes usually lose less weight on drugs in this family5, which helps explain why the pounds lost in this new trial are lower than in the obesity trials.
Side effects and what the data does not show yet
In this trial, side effects were generally similar on the two drugs, Business Insider reported. Slightly more people on retatrutide had diarrhea, while constipation was slightly more common on Ozempic1. People on retatrutide also had slightly higher rates of dysesthesia, a rare side effect that causes tingling or skin-on-fire sensations1. In Lilly’s earlier obesity trial, this skin sensation affected 12.5% of people on the 12 mg dose, compared with 0.9% on placebo; Lilly said it was mostly mild to moderate5.
Several things are still unknown:
- The full numbers. The results came in a company announcement released the day before Lilly’s quarterly earnings report1. Outside scientists have not yet reviewed how the trial was analyzed or the detailed safety data.
- How many people stopped. The reports on this trial do not give dropout rates. In the earlier obesity trial, 11.3% of people on the 12 mg dose stopped because of side effects, compared with 4.9% on placebo5.
- Heart attacks and strokes. Better cholesterol and blood pressure numbers are not the same as fewer heart attacks. A separate trial of about 10,000 people is set up to answer that question and is not expected to finish before 20296.
- Comparison with Mounjaro. This trial compared retatrutide with Ozempic, which copies one hormone. A head-to-head trial against tirzepatide (Mounjaro, Zepbound) is still running, with completion estimated for December 20266.
The news reports did not name the trial. The public trial registry lists a Lilly study comparing retatrutide head to head with semaglutide, the drug in Ozempic, in about 1,250 people with type 2 diabetes, with blood sugar at 80 weeks as its main measure6.
Who is behind the results
Every Phase 3 trial of retatrutide listed in the public registry is sponsored by Eli Lilly6, which makes both retatrutide and Mounjaro1. Ozempic is made by its main rival, Novo Nordisk1. The figures reported so far come from Lilly itself.
Lilly expects to ask the US Food and Drug Administration for approval in early 20272. Sources differ on how soon the drug could reach patients. Business Insider reported it could be available sometime next year if all goes well, for uses including obesity, obesity-related sleep apnea and knee arthritis1. PepiScreen, a site that tracks the gray market, noted that FDA review typically takes around 10 to 12 months after filing, which would put a US approval in late 2027 or 2028, if it is approved at all7.
A busy gray market before approval
Retatrutide is not approved by any regulator anywhere in the world7. Even so, sellers overseas are shipping powders labeled “reta,” and some bodybuilders are injecting it themselves1. In an unusual step, Lilly addressed this in its announcement: “Anyone purporting to sell retatrutide to consumers is breaking the law,” the company said1.
Regulators have found problems with some of these products. In Australia, testing of a vial sold as retatrutide found none of the drug; it contained undeclared semaglutide instead7. Health officials in the Australian state of Victoria reported six cases of sudden liver injury in people who had used unapproved products labeled retatrutide, possibly linked to a contaminant7. In August 2026, Lilly filed six federal lawsuits in the United States against businesses selling retatrutide7.
How it fits the field
Drugs that copy gut hormones have become the main medicine-based approach to weight loss, and drugmakers are racing to build stronger versions. Novo Nordisk is testing its own next drug, CagriSema, which is expected to seek FDA approval by the end of this year4. Neither retatrutide nor CagriSema is approved4. Ozempic and Mounjaro are approved for type 2 diabetes, and Wegovy and Zepbound for weight management4.
Some observers have said retatrutide could rival weight-loss surgery in results1. That comparison rests on average weight loss in trials, not on long-term health outcomes. Biohack has also covered what happens when people stop drugs in this family, including a gut procedure tested to limit weight regain after Zepbound.
