You have probably heard about weight-loss shots by now. A friend, a co-worker or maybe your own doctor has brought them up.
Now a newer option is moving through late-stage trials, and it works a little differently from the ones already on pharmacy shelves.
The drug is called retatrutide. In a large 80-week trial reported in the New England Journal of Medicine on September 29, 2026, adults with obesity lost roughly a quarter of their body weight on the highest dose. Placebo group participants lost about 4 percent.
Retatrutide is an investigational once-weekly injection from Eli Lilly. It has not yet been approved by the US Food and Drug Administration or any other regulator.
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How retatrutide differs from Ozempic and Mounjaro
Existing shots activate one or two of the body's gut-hormone signals.
Wegovy, the higher-dose form of semaglutide, works only on the GLP-1 pathway.
Mounjaro, whose active ingredient is tirzepatide, hits both GLP-1 and GIP, which is thought to explain part of its stronger effect.
Retatrutide adds a third target, the glucagon receptor. That signal tends to raise the body's energy use rather than just curb appetite. In short, it is designed to burn a little more while asking you to eat a little less.
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What the trial actually showed
The trial, called TRIUMPH-1, enrolled 2,339 adults with obesity and without type 2 diabetes across sites in 11 countries.
Participants were randomly assigned to weekly injections of retatrutide at 4 mg, 9 mg or 12 mg, or to placebo, for 80 weeks.
Average weight loss reached about 25 percent at the 12 mg dose. Around 65 percent of that group dropped below the medical threshold for obesity, a body mass index under 30.
Similar patterns showed up in related conditions. Knee pain eased in participants with osteoarthritis, and breathing pauses during sleep fell in people with obstructive sleep apnea.
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Side effects were mostly digestive and matched what has been reported with other GLP-1 medications.
Nausea, diarrhea, constipation and vomiting were more common in the retatrutide groups. About one in nine people on the highest dose stopped treatment because of side effects.
Blood sugar and inflammation improved too
A separate trial in adults with obesity and type 2 diabetes, reported in The Lancet the same day, tracked what the drug does to blood sugar.
On the 12 mg dose, roughly seven in ten reached a HbA1c reading of 6.5 percent or lower. That is a common threshold for good glycemic control. Fewer than three in ten placebo participants hit it.
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Blood pressure, cholesterol and triglycerides also improved. So did high-sensitivity C-reactive protein, a marker of low-grade inflammation in the blood.
In practice, the metabolic profile people worry about at annual checkups shifted in a healthier direction.
Where retatrutide stands in the approval process
Eli Lilly is running a broader Phase 3 program called TRIUMPH covering obesity, diabetes and cardiovascular disease. Several of those trials are still reading out through late 2026.
Regulators including the FDA will need to review the full package before deciding whether to approve retatrutide.
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Until then, no pharmacy can dispense it, and any decision about switching or starting a weight-loss drug belongs in a conversation with your own physician.
This article is made and published by Ida-Marie Palm Varbæk, who may have used AI in the preparation.