# Who are Merck & Co.'s customers? Who does Merck & Co. earn revenue from?
Canonical: https://valuechain.wiki/merck-co · Facet: customers · Updated: 2026-09-11T15:35:54.858698+00:00 · Source: ValueChain.wiki (cited money-flow graph)

**Citable summary**: Merck & Co.'s confirmed revenue counterparties include McKesson Corporation plus 2 undisclosed/aggregate relationships. Per the valuechain.wiki graph: 3 revenue edges, backed by 3 dated sources, 2 of them primary filings (as of 2026-09-11).

### 종양내과 시장 (키트루다) (high)
- metric: Amount $31.7B · 2025 키트루다 매출 · 10-K
- note: Keytruda is the world's best-selling drug at $31.68B in 2025 (+7%); subcutaneous switch underway ahead of the 2028 US patent cliff.
- [confirms] Merck & Co. (SEC EDGAR) (EN, filing, published 2026-02-24) https://www.sec.gov/Archives/edgar/data/310158/000031015826000063/mrk-20251231.htm: "In 2025, sales of Keytruda represented 49% of the Company's total sales ($31,680M); US composition-of-matter patent expires 2028."
- [mentions] Wells Fargo·BofA (via Investing.com) (EN, research, published 2026-01-15) https://www.investing.com/news/analyst-ratings/bmo-capital-raises-merck-stock-price-target-on-potential-keytruda-patent-extension-93CH-4484365: "Analyst consensus ~$118 (Wells Fargo Overweight $135, BofA Buy $132); thesis hinges on the post-Keytruda diversification engine and 2028 cliff mitigation."

### 백신·동물약·비항암 (가다실·애니멀헬스·윈리베어 등) (high)
- metric: Amount $6.4B · 2025 · Animal Health 2025 sales (non-oncology diversification)
- note: The axis diversifying away from Keytruda concentration (49% of total) and a buffer to the 2028 patent cliff — Animal Health $6.35B (+8%), Gardasil $5.23B (down from $8.58B), Winrevair $1.44B, alliance revenue Lynparza $1.45B and Lenvima $1.05B. Vaccines and animal health have low correlation to the human-oncology cycle, lowering earnings volatility.
- [confirms] Merck & Co. (SEC EDGAR) (EN, filing, published 2026-02-24) https://www.sec.gov/Archives/edgar/data/310158/000031015826000063/mrk-20251231.htm: "2025 sales: Gardasil/Gardasil 9 $5,233M, Winrevair $1,443M, Animal Health $6,354M (Livestock $3,896M, Companion $2,458M); alliance revenue Lynparza $1,450M, Lenvima $1,053M."

### 맥케슨 (high)  → /mckesson.md
- note: Merck sells its products to McKesson as a wholesaler customer and disclosed in the reverse filing that about 22% of its year-end 2025 accounts receivable was attributable to McKesson, which reflects Merck's accounts receivable rather than McKesson's supplier-spend share.
- [confirms] Merck & Co., Inc. (EN, filing, published 2026-02-24) https://www.merck.com/wp-content/uploads/sites/124/2026/02/MRK-12.31.2025-10K-FINAL.pdf: "McKesson Corporation represented approximately 22% of total accounts receivable at December 31, 2025."

Reverse side: https://valuechain.wiki/merck-co/suppliers.md · Ripple: https://valuechain.wiki/merck-co/ripple.md

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Full node: https://valuechain.wiki/merck-co.md · JSON: https://valuechain.wiki/merck-co.json