Lilly's Zepbound and Mounjaro Dominate Q3, Surpassing Keytruda in Sales

Eli Lilly's incretin-based medications for obesity and diabetes have delivered a groundbreaking performance in the third quarter of 2025, with combined sales of Zepbound and Mounjaro reaching $10.1 billion. This milestone marks a significant shift in the pharmaceutical landscape, as the duo has now surpassed Merck's cancer blockbuster Keytruda in quarterly revenue.

Zepbound Defies Formulary Exclusion with Strong Growth

Despite facing a potential setback when CVS Caremark, the largest U.S. pharmacy benefit manager, removed Zepbound from its formulary in July, Lilly's obesity treatment has shown remarkable resilience. Sales of Zepbound reached nearly $3.6 billion in Q3, representing a staggering 185% year-over-year growth and exceeding analyst expectations by more than $500 million.

The impact of the CVS formulary exclusion appears to have been mitigated by Lilly's direct-to-consumer sales channel, LillyDirect. This platform, which offers certain medicines at a discount to out-of-pocket payers, has become increasingly important in maintaining Zepbound's growth trajectory.

Mounjaro Continues to Exceed Expectations

Mounjaro, Zepbound's sister medication for diabetes, also outperformed market projections with Q3 revenues of $6.5 billion. The drug's sales grew 109% compared to the same quarter in 2024, surpassing both Citi and consensus forecasts by approximately $1 billion.

The collective performance of tirzepatide-based treatments has propelled Lilly to new heights, with the company reporting overall sales growth of 54% year-over-year, reaching $17.6 billion for the quarter.

Lilly Raises Guidance Amid Strong Performance

In response to the exceptional Q3 results, Eli Lilly has revised its full-year guidance upward. The company now anticipates 2025 sales to fall between $63 billion and $63.5 billion, an increase from the previous forecast of $60 billion to $62 billion.

While Zepbound and Mounjaro have been the primary drivers of growth, Lilly's breast cancer treatment Verzenio also contributed to the company's success, albeit with more modest gains. Verzenio sales grew 7% to $1.47 billion, slightly below analyst expectations.

As Lilly continues to dominate the incretin market, the company is looking ahead to the potential launch of its oral GLP-1 asset, orfoglipron, expected sometime next year. The success of the current incretin franchise bodes well for this upcoming addition to Lilly's portfolio, potentially solidifying the company's position at the forefront of metabolic disease treatment.