What did the retatrutide trials find?
Eli Lilly’s experimental obesity shot, retatrutide, did well in two late-stage trials. In one, published Tuesday in the New England Journal of Medicine, people without diabetes on the top dose lost about a quarter of their body weight over 80 weeks. In the second, in The Lancet, people with type 2 diabetes lost about 19%.
Lilly plans to ask the FDA for approval early next year. Meanwhile, vials marked “research use only” sell online for up to $600.
Why obesity drugs now work like a subscription.
For years, Lilly and Novo Nordisk told insurers, employers and Congress that obesity is a chronic disease, like diabetes. Chronic diseases need lifelong treatment, the companies argued, and insurance should pay for it.
People taken off Zepbound in a 2024 trial regained 14% of their body weight within a year. Dr. Fatima Cody Stanford, an obesity medicine physician-scientist at Massachusetts General Hospital and Harvard Medical School, tells her patients they are “potentially long-term treatment.” (Lilly and Novo Nordisk have both paid her consulting fees. So have Boehringer Ingelheim and Amgen, which are testing rival obesity drugs.)
Insurers and states have been less willing to pay. Four state Medicaid programs have dropped obesity-drug coverage since last fall. Several Massachusetts insurers dropped it too, and GLP-1 use in the state fell sharply. CMS has delayed the Part D portion of its planned GLP-1 coverage model.
So the drugmakers started selling directly to patients for cash. Lilly lists Zepbound at $299 to $449 a month. Novo now calls Wegovy buyers “customers” and tells them to “Live lighter.”
In any other industry, a lifelong product with a monthly cash price is a subscription. Obesity has become a subscription disease.
Cost and side effects top the reasons people stop.
About 4 in 10 commercially insured people stop these drugs within a year. Older studies put it higher, at 50% to 65%. “That is consistent with the real-world challenges we see,” Dr. Stanford told me. Her patients stop because of “cost or loss of insurance coverage, prior-authorization barriers,” side effects and “injection fatigue.”
In one study of 125,474 patients, clinical notes most often cited side effects and cost as the reasons people stopped. Among patients with diabetes, those with estimated incomes over $80,000 quit at a lower rate than those under $30,000.
Across the GLP-1 drug class, more weight loss has come with more side effects. In the TRIUMPH-1 trial, about 4 in 10 people on the top dose had nausea. About 1 in 8 felt burning or tingling skin. “A roughly 1-in-8 rate at the highest dose is not trivial,” Dr. Stanford said. About 1 in 11 had low blood pressure, including people taking no blood pressure pills. “We should not assume it is only a medication-interaction issue,” she said.
How are people getting GLP-1 drugs?
While direct sales may reach people who aren’t actually overweight or obese, they miss medically eligible patients who can’t afford $449 a month. “Ability to pay is increasingly influencing who can start and, especially, who can stay on treatment,” Dr. Stanford said. Direct sales “may help some people,” she added, but “they can create a two-tiered system in which treatment continuity depends on disposable income.”
Retatrutide has no approved route to patients except clinical trials and a narrow Lilly early-access program. Before that, Lilly gave the drug to one 79-year-old man through compassionate use. STAT News asked the White House several times whether he was President Trump, also 79 at the time. Afterward, White House spokesperson Kush Desai said on X the request wasn’t for the president.
Online sellers offer vials on a gray market. So do some doctors and nurse practitioners. In June, my CBS News colleagues found more than 120 websites selling or promoting retatrutide, including more than 50 clinics with licensed staff. Two Los Angeles clinics listed it at $330 and $450 a month, about what Lilly charges for Zepbound. Since 2024, the FDA has sent 14 warning letters to sellers. At least six kept offering it. Poison centers logged about 95 retatrutide exposures a month in early 2026, up 265% from late 2025.
What additional research is needed?
Dr. Stanford won’t offer retatrutide outside a trial until the FDA approves it. She wants “larger and longer studies,” starting with “cardiovascular safety, including heart rate and rhythm effects.”
For the burning skin, she wants to know “where the symptoms occur, how long they last, whether they recur with dose escalation.” She asks what rapid weight loss does to “lean mass, nutrition, hydration, and gallbladder disease,” especially in older adults. She also wants data on what happens after people stop, and on patients with several chronic conditions.
A late-stage trial is now testing retatrutide against tirzepatide, the drug in Zepbound. Until it reports, “it would be premature to conclude that retatrutide is clinically superior,” Dr. Stanford said. “My concern is that enthusiasm can outrun the evidence.”
Lilly plans to file for FDA approval early next year.