Is Eli Lilly Stock Too Dependent On Two Drugs?

Two drugs, Mounjaro and Zepbound, accounted for $14.9 billion of Eli Lilly’s (LLY) $23.0 billion in revenue during fiscal Q2 2026. This leaves Eli Lilly relying on two medicines for most of its sales at a time when the price it gets for them is falling. So why is so much of Eli Lilly’s business running through two drugs?

More Patients Are Taking Mounjaro And Zepbound

Eli Lilly is selling far more of both drugs. U.S. revenue rose 33% in fiscal Q2 2026, which management said came primarily from volume growth of Zepbound and Mounjaro. The pattern abroad was the same: in China, revenue grew 93% in constant currency on the uptake of Mounjaro.

More people can now get the drugs paid for, too. The Medicare GLP-1 Bridge program launched on July 1, 2026, and management said that with it, 35% more people in the U.S. have coverage for its obesity medicines. A drug’s sales equal the number of prescriptions filled multiplied by the price Lilly keeps after rebates and discounts, and so far the number of prescriptions has been rising fast.

How Much Of Lilly’s Growth Comes From Two Drugs?

Most of it: Mounjaro and Zepbound added $6.3 billion of revenue in fiscal Q2 2026 over the same quarter a year earlier, out of about $7.4 billion added across the whole of Eli Lilly.

That growth occurred while prices moved the other way. Excluding adjustments to estimates for rebates and discounts, prices across all of Lilly’s U.S. sales fell 9% in the quarter. Management said the decline came from Zepbound and Mounjaro. Management also said it expects price to go down, noting that this is built into its guidance. So each quarter, Lilly must fill more prescriptions of the same two drugs to make up for the lower price it gets on each one.

What Does Eli Lilly’s Share Price Assume?

The share price likely assumes that Mounjaro and Zepbound keep growing. Eli Lilly stock trades at 41.4 times its earnings over the last twelve months, against 22.9 for the S&P 500. Buyers have paid up as the business grew, and the stock returned 52.3% over the year to October 19, 2026, against 17.4% for the index.

There is a fair case against the worry. Outside the two drugs, management said the Oncology, Immunology and Neuroscience medicines in its Key Products group together grew 121% in fiscal Q2 2026 from a year earlier.

The dependence is a real risk for investors to monitor, though so far Lilly has sold enough extra prescriptions to grow quickly despite the lower price. The U.S. price on Zepbound and Mounjaro is the number to watch when Eli Lilly reports fiscal Q3 2026 results, expected on or around October 29, 2026.

Does This Mean You Should Act On LLY?

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