Retatrutide Trial Shows Up to 60-Pound Loss in Type 2 Diabetes

Weight loss in the hardest patients to treat

Eli Lilly's experimental triple-hormone drug retatrutide has now posted results in the patient group where weight-loss drugs usually do worst: people with type 2 diabetes. The 80-week phase 3 TRIUMPH-2 trial enrolled 1,152 adults with type 2 diabetes who also had obesity or overweight. They were assigned to weekly retatrutide at 4 mg, 9 mg or 12 mg, or to placebo.13 Average weight loss was 29.8 pounds on the lowest dose, 45.4 pounds on the middle dose and 49.6 pounds (20.8% of body weight) on the top dose. The placebo group lost 9.3 pounds.16 The "up to 60 pounds" figure in the headlines comes from a subgroup. Participants who started with a BMI of 35 or higher lost an average of 60.8 pounds, or 23.4%, on the 12 mg dose.14

Scientific American called the result a first for the field: no drug had previously averaged more than 20% weight loss in people with type 2 diabetes.16 That matters because people with diabetes generally lose less weight on incretin drugs than people without it. TRIUMPH-2 was designed to show how retatrutide performs in that harder group.14 By the end of the study, 59.5% of people on the top dose no longer met the BMI definition of obesity.14

The detailed results came out on September 29, 2026. They were presented at the EASD meeting in Milan and published in The Lancet the same month.3119 Overall, the coverage tells a consistent story of record-setting weight loss. The differences between outlets come down mostly to which statistical analysis they report.

Where the coverage diverges

Most outlets use Lilly's "efficacy estimand" figure of 20.8% for the 12 mg dose.1220 That analysis estimates what happens when people keep taking the drug as prescribed. Pharmacy Times, covering the EASD presentation, reported a top figure of 18.8%.33 The most likely reason is that it used a stricter analysis that counts everyone who was randomized, including people who stopped treatment. That gap is worth keeping in mind. Lilly's own headline numbers come from the more favorable analysis.

The bigger disagreement is about how to read the blood-sugar results. Fierce Biotech stressed that A1C, the standard measure of long-term blood sugar, fell by 1.4 to 1.6 percentage points from a starting level of 7.7%, compared with 0.2 points on placebo. Higher doses did not lower it further.12 Fierce also noted that about 40% of patients on the two higher doses reached A1C levels in the normal range. In an earlier trial of Lilly's tirzepatide, up to 55.3% did.12 Most trade coverage instead presents retatrutide as a drug that improves blood sugar and weight together, which is how Lilly frames it.17

The more skeptical reading is the right one. Retatrutide is a weight-loss drug first. Its blood-sugar benefit is real and large compared with placebo, but it does not clearly beat what tirzepatide already offers. A separate 40-week diabetes trial, TRANSCEND-T2D-1, lowered A1C by 1.7 to 2.0 points, and weight loss was still continuing at the end of the study.1514 One trade write-up of that trial gave both 16.8% and "roughly 15%" as the top weight-loss figure.17 Even summaries of the same data are not always consistent.

The safety picture is getting clearer

The Lancet paper added a second safety signal to the one that has followed retatrutide since December. Low blood pressure (hypotension) affected 1%, 5% and 6% of patients on the three doses, compared with under 1% on placebo.32 Pharmacy Times advised caution for patients already taking blood-pressure drugs, since retatrutide itself lowers blood pressure.33 Dysesthesia, an altered or heightened skin sensation such as tingling or burning, affected 4.5% to 7.3% of patients in TRIUMPH-2, compared with 0.7% on placebo.31 Lilly says most cases were mild to moderate and cleared up during treatment.31 However, neither the TRIUMPH-2 announcement nor the TRIUMPH-1 paper reports how long the symptoms lasted.31

Dysesthesia rates have varied widely from trial to trial. On the 12 mg dose they ranged from 20.9% in the knee osteoarthritis trial to 4.4% in TRANSCEND-T2D-1.34 Tirzepatide's US label lists the side effect at 0.4%.34 Discontinuation was uneven in TRIUMPH-2: 11.6% of people on the 9 mg dose stopped because of side effects, compared with 7.7% on 12 mg and 4.9% on placebo.32 The fact that the middle dose had more dropouts than the top dose suggests tolerability is not a simple function of dose. Prescribers will probably have to learn their own titration habits.

Five wins and a filing date

TRIUMPH-2 is one of five positive phase 3 studies for retatrutide.13 The best weight-loss figures come from TRIUMPH-1, which enrolled people without diabetes. Patients on 12 mg lost 70.3 pounds (28.3%) over 80 weeks. Those who continued in an extension lost 85 pounds (30.3%) by week 104, with no sign of a plateau.11 TRIUMPH-3 enrolled people with severe obesity and established heart disease. Average weight loss there reached 55.8 pounds (22.6%).13 That trial measured weight, though, and its results do not show that the drug prevents heart attacks or strokes.14

Lilly's second-quarter report says the data package is complete for obesity, sleep apnea and knee osteoarthritis pain. The company plans to file for US approval in the first quarter of 2027.10 On a normal review timeline, approval would come no earlier than late 2027.10 The main open question is TRIUMPH-5, which tests retatrutide directly against tirzepatide. Comparisons across separate trials cannot answer that question.14

The FDA's fast lane has already helped Lilly

A faster review is possible, because Lilly has done it before. The FDA approved the company's oral GLP-1 pill orforglipron, sold as Foundayo, on April 1, 2026. It was the fifth approval under the Commissioner's National Priority Voucher pilot program.1 The decision came 50 days after filing, which makes it the fastest approval of a new molecular entity (a drug with a new active ingredient) since 2002.7 Foundayo is approved for obesity. Lilly has also filed it for type 2 diabetes in the US. Separately, a European Medicines Agency committee recommended EU approval for both uses on October 15.7 If the FDA treats retatrutide the same way, approval could arrive well before the late-2027 estimate. So far, though, Lilly has only announced a filing date, and no voucher has been reported.

Pricing: more patients, lower prices

What retatrutide eventually costs will be shaped by a market where prices are already falling. Under Lilly's agreement with the White House, Medicare patients pay no more than $50 a month for Foundayo and the multidose Zepbound pen. The deal also lets state Medicaid programs expand access.9 Foundayo's cash prices on LillyDirect, Lilly's direct-to-consumer pharmacy, start at $149 a month, with temporary discounts on some doses through the end of 2026.3 Self-pay offers for both the Wegovy pill and Foundayo now fall roughly between $149 and $299 a month.6

The effect shows up in Lilly's financial results. Second-quarter revenue rose 48% to $22.97 billion. The volume of medicine sold rose 60%, while the average price Lilly collected fell 13%.21 Outside the US, realized prices fell 36%, mainly because Mounjaro was added to China's national reimbursement list.21 Management has said further price declines are built into its guidance.26

Obesity drug sales and how much Lilly relies on them

Mounjaro brought in $9.94 billion in the quarter, up 91%. Zepbound added $4.93 billion.27 Together, the two brand names for tirzepatide made up 65% of Lilly's revenue, up from 16% in 2023.27 Lilly raised its 2026 revenue forecast to $85 billion to $87 billion.24 By the end of the second quarter, Zepbound accounted for nearly 60% of prescriptions in the US branded obesity market.22 Novo Nordisk, meanwhile, expects 2026 adjusted sales to be flat or down as much as 6%.27

Lilly has other products too. Its oncology, immunology and neuroscience drugs grew 121% as a group in the second quarter.26 It also spent $2.8 billion in the quarter on acquired research programs, including several deals.29 Even so, those businesses are small next to tirzepatide.

That explains retatrutide's strategic role. Lilly needs a successor that offers enough extra weight loss to hold up prices while tirzepatide's per-patient revenue keeps falling. TRIUMPH-2 makes that case for patients with diabetes, though not in its blood-sugar results. The next test comes on October 29, when Lilly reports third-quarter results.23 The figures to watch are how much of the growth comes from volume versus price.26