Eli Lilly's Most Promising Weight Loss Drug May Come With a Surprising Benefit: Pain Relief

The rising popularity of weight loss drugs is a key reason healthcare company Eli Lilly (NYSE: LLY) has been soaring in value in recent years. It has a leading GLP-1 drug that's approved for diabetes (Mounjaro) and weight loss (Zepbound). Those products are generating billions in revenue for the business every quarter.

What's encouraging, however, is that there may be more benefits with GLP-1 drugs than simply losing weight and controlling blood sugar. Lilly is developing a GLP-1 drug that has shown in a recent trial that it can also help with pain relief. That could be a promising development for multiple reasons.

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Another big catalyst could be on the horizon for Eli Lilly

One of the most promising drugs to watch for from Lilly in the near future is retatrutide. It's referred to as a "triple G" drug in reference to the multiple hormones it targets: GIP, GLP-1, and glucagon. This goes further than the currently approved GLP-1 drugs, and the early results from retatrutide have been promising.

Last month, management announced phase 3 trial results showing that patients who had been taking a 12-milligram dosage of retatrutide had lost 28.7% of their body weight, on average, at the 68-week mark. By comparison, tirzepatide, which is the active ingredient in Mounjaro and Zepbound, had an average weight loss of 26.6% in a study that came out in 2023, but that was for patients who also underwent 12 weeks of "intensive lifestyle intervention."

Plus, a further benefit that retatrutide may offer is pain relief. Participants in this most recent trial included people with obesity and knee osteoarthritis. And more than 1 out of 8 of them said they were free of knee pain by the end of the trial.

Expanding the use of GLP-1 drugs could drastically enhance Eli Lilly's growth

GLP-1 drugs are highly coveted for their ability to help people lose weight. But if there are added benefits, such as reducing pain or treating sleep apnea and reducing cardiovascular risk, that can lead to greater coverage from health insurers and result in even more demand.

In 2024, the Food and Drug Administration approved Zepbound as a treatment for moderate to severe obstructive sleep apnea. Over time, retatrutide may also rack up indications and prove to be an even better drug for Lilly.

In the company's most recent quarter, which ended on Sept. 30, 2025, Lilly's revenue rose by 54%, totaling $17.6 billion. Mounjaro and Zepbound generated a combined $10.1 billion and were responsible for the vast majority of that growth. If the company gets another approved GLP-1 drug in its portfolio, that can bolster these results even further. And it may obtain approval for a GLP-1 pill later this year (currently, the company's approved treatments are injectables).

There's still a lot more growth ahead for Lilly, which is why investors remain bullish on the healthcare stock.

Eli Lilly's stock is expensive, but the premium may be justifiable

Currently, the stock trades at a price-to-earnings multiple (P/E) of more than 50. That's a hefty valuation, but when you consider the company's impressive growth of late, plus the potential for its top and bottom lines to surge even higher, then the price tag doesn't seem so unreasonable. As the company's financials improve due to its growth, that P/E multiple is likely to come down -- unless, of course, the stock takes off again.

Eli Lilly is a solid long-term investment as it builds out a strong portfolio of GLP-1 drugs. Last year, it rose by 39% and briefly joined the trillion-dollar club. Although it has dipped from those highs, the stock is likely to go far higher in the future; it's a good investment to buy and hold.

David Jagielski, CPA has no position in any of the stocks mentioned. The Motley Fool has no position in any of the stocks mentioned. The Motley Fool has a disclosure policy.