Eli Lilly (LLY) has delivered dramatically faster revenue growth than Merck (MRK) over the 2022–2025 period. LLY grew revenues from $28.5B in FY2022 [LLY:Q0] to $65.2B in FY2025 [LLY:Q3], representing a roughly 128% cumulative increase and a ~32% CAGR, fueled primarily by its GLP-1 franchise (tirzepatide). MRK, by contrast, grew revenues from $59.3B in FY2022 [MRK:Q0] to $65.0B in FY2025 [MRK:Q3], a more modest ~10% cumulative gain and a ~3% CAGR. Notably, LLY's FY2025 revenues of $65.2B [LLY:Q3] have now essentially caught up to MRK's $65.0B [MRK:Q3], having started the period at less than half of MRK's base. MRK did show meaningful acceleration from FY2023 ($60.1B [MRK:Q1]) to FY2024 ($64.2B [MRK:Q2]), but the pace remains far below LLY's explosive trajectory, which saw revenues jump ~32% from FY2023 ($34.1B [LLY:Q1]) to FY2024 ($45.0B [LLY:Q2]) and another ~45% from FY2024 to FY2025.
MRK: Merck has grown steadily but modestly, with revenues rising from $59.3B in FY2022 [MRK:Q0] to $65.0B in FY2025 [MRK:Q3], a cumulative gain of roughly 10% over three years. The company showed its strongest single-year step-up between FY2023 ($60.1B [MRK:Q1]) and FY2024 ($64.2B [MRK:Q2]), but overall growth remains incremental rather than transformational.
LLY: Eli Lilly has been one of the fastest-growing large-cap pharma companies in recent history, with revenues nearly tripling from $28.5B in FY2022 [LLY:Q0] to $65.2B in FY2025 [LLY:Q3], driven by the rapid commercial uptake of its GLP-1 and diabetes portfolio. The acceleration has been consistent and steep, with revenues surging from $34.1B in FY2023 [LLY:Q1] to $45.0B in FY2024 [LLY:Q2] and then to $65.2B in FY2025 [LLY:Q3], reflecting extraordinary demand that has now brought LLY's top line to parity with the much larger MRK.
Both MRK and LLY face a broadly similar landscape of risk factors centered on patent and exclusivity cliffs, generic and biosimilar competition, third-party and outsourcing dependencies, and supply-chain vulnerabilities, though the evidence highlights some differences in emphasis. MRK explicitly flags the rapid and significant loss of sales as products lose market exclusivity and the threat that generic or biosimilar entrants may offer equally effective products at substantially lower prices [MRK:S2][MRK:S0], while also calling out unique risks tied to its biologics and vaccines portfolio—including limited access to biological materials and the long, complex development process [MRK:S4]. MRK additionally identifies climate-related physical risks—such as increased frequency and severity of extreme weather events—as an acute-to-chronic operational threat [MRK:S1], though the specific manifestations cited in its disclosures extend to a range of climate hazards. LLY similarly highlights the complexity and evolving regulatory environment for biosimilars, noting that health authority guidelines could make it less burdensome for competitors to enter [LLY:S0], and places notable emphasis on supply-chain disruptions that have already resulted in delays, product shortages, lost revenue, and potential market exits in select geographies [LLY:S1]. Both companies cite outsourcing risks—including third-party failure to meet standards, protect confidential information, or perform reliably—as a material concern [MRK:S3][LLY:S2]. LLY additionally flags risks from business development activities such as failed diligence, unsuccessful clinical trials, and manufacturing and commercialization challenges associated with acquired or partnered programs [LLY:S3].
MRK: MRK's risk profile is anchored by patent dependence and the well-documented revenue cliff when exclusivity lapses, with generic and biosimilar entrants able to undercut on price for products that may be equally safe and effective [MRK:S0][MRK:S2]. The company also carries distinctive exposure through its biologics and vaccines business, where supply of biological materials is constrained and the development pathway is unusually long and uncertain [MRK:S4], and it separately flags physical climate risks—including increased frequency and severity of extreme weather events—as an operational concern [MRK:S1].
LLY: LLY faces intensifying biosimilar competition risk, with regulatory frameworks globally still evolving in ways that could lower barriers for competitors [LLY:S0], and has already experienced real-world supply-chain disruptions leading to product shortages and pauses in select markets [LLY:S1]. Its growing reliance on contract manufacturers, AI vendors, and other third parties introduces additional execution and data-security risks [LLY:S2], while an active business development strategy adds exposure to diligence failures, unsuccessful clinical trials, and the inherent uncertainties of manufacturing and commercializing new programs [LLY:S3].