Eli Lilly’s New Obesity Treatment Shows Weight Loss Up To 71.2 Lbs, Reduces Pain In Trial

Eli Lilly’s new late-stage trial results of retatrutide showed about 28% weight loss in participants, the company said.
The entrance to the Eli Lilly factory in Kinsale, Co Cork, where weight loss drug Mounjaro is made. Picture date: Sunday May 18, 2025.
The entrance to the Eli Lilly factory in Kinsale, Co Cork, where weight loss drug Mounjaro is made. Picture date: Sunday May 18, 2025. (Photo by Niall Carson/PA Images via Getty Images)
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Aashika Suresh·Stocktwits
Updated Dec 11, 2025   |   9:05 AM EST
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  • In addition, the obesity drug also improved knee pain in participants, Eli Lilly noted. 
  • Seven additional Phase 3 trials for the treatment are expected to be completed in 2026, the company said. 
  • Earlier this year, Eli Lilly became the first pharmaceutical company to hit a market value over $1 trillion. 

Eli Lilly and Co. (LLY) announced that results from the phase 3 trial of its latest obesity treatment showed significant weight loss and reductions in knee pain among participants. 

A 12 mg dose of retatrutide, Eli Lilly’s once-weekly triple hormone receptor agonist, delivered weight loss of about 71.2 lbs or 28% of participants’ body weight, according to the statement from the company. It also reduced knee pain in those with osteoarthritis.

Shares of LLY were up about 3% in premarket trading on Thursday. 

Retatrutide Results

In TRIUMPH-4, a Phase 3, 68-week trial, Eli Lilly found that in addition to weight loss, the retatrutide reduced knee pain, tracked using the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) score, by up to an average of 4.5 points (75.8%). It also significantly improved participants' physical function, with more than one in eight patients allegedly completely pain-free at the end of the trial. 

Eli Lilly added that seven additional Phase 3 trials for the obesity and type 2 diabetes treatment would be completed in 2026. 

“People with obesity and knee osteoarthritis often live with pain and restricted mobility, and may eventually require total joint replacement," Kenneth Custer, executive vice president and president, Lilly Cardiometabolic Health, said. 

He added that the company was encouraged by the latest results and that retatrutide could become “an important option for patients with significant weight loss needs and certain complications, including knee osteoarthritis."

Obesity Market

Eli Lilly is among the top manufacturers of weight-loss drugs worldwide, and the FDA has already approved its Zepbound. Mounjaro, a diabetes drug that also acts to reduce weight, is also FDA-approved. 

Morgan Stanley estimated earlier this year that the global weight-loss drug market will balloon to $150 billion by 2035, up from $105 billion. That is about a 10x growth from the $15 billion market in 2024.

Riding on this wave, Eli Lilly joined the ‘trillion-dollar club’ last month when its market value shot past $1 trillion. It is the first pharma company to have done so. 

How Did Stocktwits Users React?

On Stocktwits, retail sentiment around LLY remained in the ‘bearish’ territory over the past 24 hours, and message volume was at ‘low’ levels at the time of writing.

On Stocktwits, retail sentiment around LLY remained in the ‘bearish’ territory over the past 24 hours, and message volume was at ‘low’ levels at the time of writing.

Shares of LLY have gained over 24% in the past year.

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