The bar for big weight loss in medicine used to be bariatric surgery. About 30% of body weight, roughly.
Eli Lilly just hit that with a weekly shot.
The top dose helped patients lose 28.3% of their weight on average over 80 weeks. That's about 70 pounds.
About 45% of the 2,339 patients in the trial lost 30% or more. That second number is the one that matters.
30% used to be the level you only got with surgery. Lilly's top scientist Dan Skovronsky called the 30% mark "an incredible number to see."
That's a fair line. The rest of the field, including Lilly's own Zepbound, tops out around 20% to 22% weight loss.
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Lilly already owns 60% of the U.S. obesity and diabetes drug market. Novo Nordisk owns 39%. The whole space could be worth $100 billion by the 2030s.
Retatrutide is the drug Lilly is using to defend that lead. It works through a "triple G" approach. That means it hits three gut hormones, not just one or two.
More targets, deeper effect. TD Cowen said in a January note that retatrutide could bring in $3.8 billion in sales by 2030.
This is the third Phase 3 win on retatrutide. The first two were on diabetes and knee pain. That puts the drug one step from a filing.
The top dose had real side effects. About 42% of patients had nausea. About 11% quit the trial because of side effects.
A lower 4-milligram dose still drove 19% weight loss. Drop-out rates at that dose were a bit lower than the placebo group, a result that surprised even Lilly's own team.
Lilly also said it saw no heart or liver issues in the data. That cleared one of the biggest worries going in.
Novo isn't standing still. It paid up to $2 billion back in March 2025 for the rights to an early triple-hormone drug from a Chinese company.
But Novo's drug is years from patients. Retatrutide is one step from filing.
Lilly also has its new daily pill, Foundayo, in the same space. That gives the company three shots on goal in obesity by next year.
Lilly walks into the rest of 2026 with both a high dose and a low dose in its pipeline. The bar in shot-based weight loss just moved up.
The race for the $100 billion obesity market has a clear leader. It also has a real moat.
A 30% weight loss number used to live in the surgery wing. Now it lives in a once-a-week shot.
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