The Revenue LinesNarrow moat

Merck & Co. (MRK) — moat facet

Keytruda is half of Merck's sales; the other half is a vaccine that broke in China, a churning portfolio and a steady animal business.

Merck reports two segments, Pharmaceutical and Animal Health1, and discloses sales by product. Grouped into four lines, its 2025 sales of $65,011 million2 were: Keytruda including Keytruda Qlex $31,681 million, Gardasil $5,233 million, other pharmaceutical products $21,228 million and Animal Health $6,354 million34.

Sales by line, 2025 ($M)Keytruda and Qlex 31,681 — 49%Other pharmaceutical 21,228 — 33%Animal Health 6,354 — 10%Gardasil 5,233 — 8%Other revenue 515 — 1%Merck Form 10-K FY2025; other pharmaceutical calculated
Half the company in one line.

A fifth, small band sits in the chart but has no page: other revenue, $515 million in 20255. Merck describes it as miscellaneous corporate revenue, including revenue hedging activities and third-party manufacturing arrangements6. It was $382 million in 2021 and $1,728 million in 20227, the jump being hedging and manufacturing that do not reflect the medicines. The five bands reconcile exactly to reported sales for 2021 to 2025, the years after the June 2021 spin-off of Organon8.

The lines are moving in different directions. Keytruda grew from $17,186 million in 20219 to $31,681 million in 2025, while Gardasil peaked at $8,886 million in 2023 and fell 39% in 202510. The other pharmaceutical products rose and fell with the COVID antiviral Lagevrio and the diabetes drugs11. Animal Health grew slowly12.

Profit by line is only partly disclosed. The Pharmaceutical segment earned about 78.7% before central research, and Animal Health about 33.5% after its own13.

The lines also differ in where they sell. Keytruda sold $18,829 million in the United States and $12,812 million elsewhere in 202514; Gardasil, after China, was split almost evenly, $2,641 million American and $2,592 million international15. Merck's American sales grew 13% to $36.5 billion in 202516, while international sales fell from 50% of the total to 44%17, so every line is becoming more dependent on the American payers who will set Keytruda's price in 2029.

None of the lines is a separate business in Merck's reporting. Keytruda, Gardasil and the other human products all sit in one Pharmaceutical segment, which earned $45,754 million of segment profit in 202518, while the $14,987 million of central research that supports them is left unallocated19. So the line pages can describe sales by product precisely and profit by product only in outline.

The lines describe a company whose growth has come from one product. Keytruda and Gardasil together were about 57.4% of sales in the second quarter of 202620; a share that keeps rising toward 2028 would mean Merck is heading into its patent dates more concentrated, not less.

Moat trajectory: Narrowing

Keytruda's share rising; Gardasil down; other lines flat to modest growth.

The number that tests this moat
Moat Explorer calc
Keytruda and Gardasil share of sales, latest quarter
About 57.4% (Q2 2026: $9,535M of $16,607M)

Concentration in the two largest products; a rising share means Merck approaches its patent dates more concentrated.

How it's calculated: Keytruda franchise ($8,366M) plus Gardasil ($1,169M) divided by total sales ($16,607M), Q2 2026 release.
Source: Moat Explorer calculation from Merck filings ↗
Dig deeper
DIG DEEPER 01
Keytruda
Keytruda sold $31.7 billion in 2025 and nearly tripled in six years, and every year it grows the eventual fall gets larger.
DIG DEEPER 02
Gardasil
Gardasil fell from $8.9 billion to $5.2 billion in two years when China stopped buying, and American sales are now the larger half.
DIG DEEPER 03
Other Pharmaceutical
Merck's other human medicines sell $21 billion a year, and each launch is racing an exclusivity loss elsewhere in the portfolio.
DIG DEEPER 04
Animal Health
Animal Health sells $6.4 billion a year at a 33.5% segment margin, a steady tenth of Merck that its Bravecto patent will test in 2027.
References
  1. ReportedMerck reports two segments, Pharmaceutical and Animal Health, and discloses sales by product.
    Merck & Co. Form 10-K for fiscal 2025 - Animal Health segment: sales by line, Bravecto, segment profit and costs. — FY2025 · publ. 24 February 2026 · source ↗
  2. ReportedGrouped into four lines, its 2025 sales of $65,011 million were: Keytruda including Keytruda Qlex $31,681 million, Gardasil $5,233 million, other pharmaceutical products $21,228 million and Animal Health $6,354 million.
    Merck & Co. Form 10-K for fiscal 2025 - Animal Health segment: sales by line, Bravecto, segment profit and costs. — FY2025 · publ. 24 February 2026 · source ↗
  3. ReportedGrouped into four lines, its 2025 sales of $65,011 million were: Keytruda including Keytruda Qlex $31,681 million, Gardasil $5,233 million, other pharmaceutical products $21,228 million and Animal Health $6,354 million.
    Merck & Co. Form 10-K for fiscal 2025 - Animal Health segment: sales by line, Bravecto, segment profit and costs. — FY2025 · publ. 24 February 2026 · source ↗
  4. Moat Explorer calcGrouped into four lines, its 2025 sales of $65,011 million were: Keytruda including Keytruda Qlex $31,681 million, Gardasil $5,233 million, other pharmaceutical products $21,228 million and Animal Health $6,354 million.
    Moat Explorer calculation from Merck's reported sales, segment and financial statement figures ($ millions unless stated). Lines 2025: Keytruda 31,641 + Keytruda Qlex 40 = 31,681; other pharmaceutical 58,142 - 31,681 - 5,233 = 21,228; Animal Health 6,354; other revenue 515; total 31,681 + 5,233 + 21,228 + 6,354 + 515 = 65,011. 2024: 29,482; 57,400 - 29,482 - 8,583 = 19,335. 2023: 53,583 - 25,011 - 8,886 = 19,686. 2022: 52,005 - 20,937 - 6,897 = 24,171. 2021: 42,754 - 17,186 - 5,673 = 19,895. Everything else 2025: 65,011 - 31,681 = 33,330. Keytruda share of sales: 11,084 / 39,121 = 28.3% (2019, continuing basis); 17,186 / 48,704 = 35.3% (2021); 25,011 / 60,115 = 41.6% (2023); 31,681 / 65,011 = 48.7% (2025); Q2 2026 8,366 / 16,607 = 50.4%. Keytruda and Gardasil Q2 2026 (8,366 + 1,169) / 16,607 = 9,535 / 16,607 = 57.4%. Qlex 463 / 8,366 = 5.5%. Keytruda growth: 31,641 / 29,482 - 1 = 7.3% (2025); 29,482 / 25,011 - 1 = 17.9% (2024); 31,641 / 17,186 = 1.84, compound (1.84)^(1/4) - 1 = 16.5% a year; 31,641 / 11,084 = 2.85 (2019-2025). US share of Keytruda 18,829 / 31,641 = 59.5%. International Keytruda 12,812 / 11,610 - 1 = 10.4%; US Keytruda 18,829 / 17,872 - 1 = 5.4%. US Keytruda share of total sales 18,829 / 65,011 = 29.0%. Royalty: 2.5% x 31,681 = 792; 6.5% x 31,681 = 2,059. Gardasil US royalty 7% x 2,641 = 185. Winrevair royalty 22% x 1,443 = 317; 22% x 419 = 92; Winrevair Q2 2026 588 x 4 = 2,352, 22% x 2,352 = 517. Segment margins: Pharmaceutical 45,754 / 58,142 = 78.7% (2025); Q2 2026 11,612 / 14,760 = 78.7% (recast basis). Animal Health 2,131 / 6,354 = 33.5% (2025); 1,938 / 5,877 = 33.0% (2024); 1,737 / 5,625 = 30.9% (2023); 1,963 / 5,550 = 35.4% (2022); 1,950 / 5,568 = 35.0% (2021); Q2 2026 636 / 1,775 = 35.8%. Unallocated research 14,987 / 58,142 = 25.8%; Animal Health research 448 / 6,354 = 7.1%. Animal Health segment profit 2,131 / 45,754 = 4.7% of Pharmaceutical. Gardasil: international 2,592 / 6,158 - 1 = -57.9%; US 2,641 / 2,083 - 1 = 26.8%; share 5,233 / 65,011 = 8.0%; share of sales 2021 5,673 / 48,704 = 11.6%, 2022 6,897 / 59,283 = 11.6%, 2023 8,886 / 60,115 = 14.8%, 2024 8,583 / 64,168 = 13.4%; Q2 2026 1,169 x 4 = 4,676. Vaccines H1 2026 2,314 + 2,361 = 4,675; H1 2025 2,607 + 2,370 = 4,977; 4,675 / 4,977 - 1 = -6.1%. Childhood vaccines growth 2,368 / 2,241 - 1 = 5.7%; 2,485 / 2,368 - 1 = 4.9%; 2,451 / 2,485 - 1 = -1.4%. Pneumococcal: Pneumovax 166 / 893 - 1 = -81%; 825 + 759 + 166 = 1,750; 1,750 / 893 = 2.0; (825 + 759) / 166 = 9.5; Capvaxive + Vaxneuvance 759 + 825 = 1,584; 1,584 / 6,494 = 24.4% of Prevnar. Animal Health: livestock 3,896 / 6,354 = 61.3%; livestock growth 3,300 / 3,295 - 1 = 0.2%, 3,337 / 3,300 - 1 = 1.1%, 3,462 / 3,337 - 1 = 3.7%, 3,896 / 3,462 - 1 = 12.5%; companion 2,458 / 2,415 - 1 = 1.8%, 2,458 / 2,273 - 1 = 8.1%; companion excluding Bravecto 2,458 - 1,100 = 1,358; rest of Animal Health 6,354 - 1,100 = 5,254; Bravecto 359 / 335 - 1 = 7%. Segment 6,354 / 5,877 - 1 = 8.1%; 5,625 / 5,568 - 1 = 1.0%; Q2 2026 1,775 / 1,646 - 1 = 7.8%; compound (6,354 / 5,568)^(1/4) - 1 = 3.4% a year; share 6,354 / 65,011 = 9.8%; 6,354 / 31,681 = 0.20 of Keytruda; 6,354 / 9,467 = 67% of Zoetis; Zoetis 9,467 / 9,256 - 1 = 2.3%. Competitors: Keytruda 31,641 / Opdivo 10,049 = 3.1. Geography: US 36,510 / 65,011 = 56.2%; China 1,939 / 6,802 - 1 = -71%; China share 4,378 / 48,704 = 9.0% (2021), 6,802 / 60,115 = 11.3% (2023), 5,494 / 64,168 = 8.6% (2024), 1,939 / 65,011 = 3.0% (2025); other regions 65,011 - 36,510 - 14,580 - 2,711 - 1,939 = 9,271. Wholesaler receivables 22% + 21% + 13% = 56% (2025); 21 + 21 + 13 = 55 (2024); 21 + 20 + 14 = 55 (2023). Januvia and Janumet: 3,324 + 1,964 = 5,288 (2021); 2,189 + 1,177 = 3,366 (2023); 1,334 + 935 = 2,269 (2024); 1,604 + 940 = 2,544 (2025). Newer products Q2 2026: 588 + 271 + 204 + 184 = 1,247; 1,247 / 8,366 = 14.9%. Bridion 1,841 / 4 = 460 a quarter. Other pharmaceutical Q2 2026 14,760 - 8,366 - 1,169 = 5,225; Q2 2025 14,050 - 7,956 - 1,126 = 4,968; 5,225 / 4,968 - 1 = 5.2%; 2025 share 21,228 / 65,011 = 32.7%. Research: 30,531 / 60,115 = 50.8% of sales (2023). Charges 2026 9.0 + 5.7 = 14.7 bn; per share 3.62 + 2.31 = 5.93. Ohtuvayre 204 x 4 = 816; 12,100 / 816 = 14.8. Tax guidance midpoints (23.5 + 24.5) / 2 = 24.0; (35.0 + 36.0) / 2 = 35.5. Balance sheet: net debt end-2025 2,589 + 46,750 - 14,565 = 34,774; end-2024 2,649 + 34,462 - 13,242 - 447 = 23,422; end-2023 1,372 + 33,683 - 6,841 - 252 = 27,962; 30 June 2026 2,825 + 51,081 - 6,849 - 292 = 46,765, cash and short-term investments 6,849 + 292 = 7,141; net debt to equity 34,774 / 52,606 = 0.66; 46,765 / 41,933 = 1.1. Net income 2023-2025 365 + 17,117 + 18,254 = 35,736. Valuation: year-end 2025 market value 261.26 bn / net income 18.254 bn = 14.3; free cash flow 2025 16,472 - 4,112 = 12,360; 12,360 / 365,090 = 3.4%. Trailing twelve months to June 2026: sales 65,011 - 31,335 + 32,893 = 66,569; net income 18,254 - 9,506 - 5,575 = 3,173. EPS guidance midpoints (5.00 + 5.15) / 2 = 5.075; (5.04 + 5.16) / 2 = 5.10; (2.66 + 2.76) / 2 = 2.71. Protection from 2026: 2043 - 2026 = 17 years; 2028 - 2026 = 2 years. Year-end P/E = market value / net income: 147.55 / 4.442 = 33.2 (2015); 162.31 / 3.920 = 41.4 (2016); 153.30 / 2.394 = 64.0 (2017); 198.69 / 6.220 = 31.9 (2018); 231.56 / 9.843 = 23.5 (2019); 206.96 / 7.067 = 29.3 (2020); 193.59 / 13.049 = 14.8 (2021); 281.30 / 14.519 = 19.4 (2022); 276.26 / 0.365 = 757 (2023); 251.65 / 17.117 = 14.7 (2024); 261.26 / 18.254 = 14.3 (2025); 365.09 / 3.173 = 115.1 (TTM). Return on average equity 2025: 18,254 / ((52,606 + 46,313) / 2) = 18,254 / 49,460 = 36.9%. Gross profit 2025 65,011 - 16,382 = 48,629; 48,629 / 65,011 = 74.8%; royalty 792 / 16,382 = 4.8% of cost of sales. Keytruda increase 2021-2025 31,681 - 17,186 = 14,495; sales increase 65,011 - 48,704 = 16,307. US sales 36,510 / 28,480 - 1 = 28%. Pharmaceutical margin 2021 30,977 / 42,754 = 72.5%. Livestock less companion 3,295 - 2,273 = 1,022 (2021); 3,896 - 2,458 = 1,438 (2025). Prevnar 6,494 / Vaxneuvance 825 = 7.9. Animal Health 2025 6,354 against Keytruda franchise Q2 2026 8,366 - product and segment totals, growth and royalties. — 2015-2026 · publ. September 2026 · source ↗
    Method: Arithmetic on figures reported in Merck's Forms 10-K and 10-Q, results releases, the Bristol Myers Squibb, Pfizer and Zoetis 10-Ks and market data; operands shown in the source line.
  5. ReportedA fifth, small band sits in the chart but has no page: other revenue, $515 million in 2025.
    Merck & Co. Form 10-K for fiscal 2025 - Item 7 MD&A and product sales note: sales by product, segment and country. — FY2025 · publ. 24 February 2026 · source ↗
  6. ReportedMerck describes it as miscellaneous corporate revenue, including revenue hedging activities and third-party manufacturing arrangements.
    Merck & Co. Form 10-K for fiscal 2025 - Item 7 MD&A and product sales note: sales by product, segment and country. — FY2025 · publ. 24 February 2026 · source ↗
  7. ReportedIt was $382 million in 2021 and $1,728 million in 2022, the jump being hedging and manufacturing that do not reflect the medicines.
    Merck & Co. Form 10-K for fiscal 2023 - product sales for 2021-2023, the Prometheus, Daiichi Sankyo and Imago charges, impairments, receivables concentration and the Zhifei distribution arrangement in China. — FY2023 · publ. February 2024 · source ↗
  8. ReportedThe five bands reconcile exactly to reported sales for 2021 to 2025, the years after the June 2021 spin-off of Organon.
    Merck & Co. Form 10-K for fiscal 2021 - the Organon spin-off, the Acceleron acquisition and 2019-2020 sales restated to continuing operations. — FY2021 · publ. February 2022 · source ↗
  9. ReportedKeytruda grew from $17,186 million in 2021 to $31,681 million in 2025, while Gardasil peaked at $8,886 million in 2023 and fell 39% in 2025.
    Merck & Co. Form 10-K for fiscal 2023 - product sales for 2021-2023, the Prometheus, Daiichi Sankyo and Imago charges, impairments, receivables concentration and the Zhifei distribution arrangement in China. — FY2023 · publ. February 2024 · source ↗
  10. ReportedKeytruda grew from $17,186 million in 2021 to $31,681 million in 2025, while Gardasil peaked at $8,886 million in 2023 and fell 39% in 2025.
    Merck & Co. Form 10-K for fiscal 2025 - vaccines and China: Gardasil, the childhood and pneumococcal vaccines, and sales in China. — FY2025 · publ. 24 February 2026 · source ↗
  11. Moat Explorer calcThe other pharmaceutical products rose and fell with the COVID antiviral Lagevrio and the diabetes drugs.
    Moat Explorer calculation from Merck's reported sales, segment and financial statement figures ($ millions unless stated). Lines 2025: Keytruda 31,641 + Keytruda Qlex 40 = 31,681; other pharmaceutical 58,142 - 31,681 - 5,233 = 21,228; Animal Health 6,354; other revenue 515; total 31,681 + 5,233 + 21,228 + 6,354 + 515 = 65,011. 2024: 29,482; 57,400 - 29,482 - 8,583 = 19,335. 2023: 53,583 - 25,011 - 8,886 = 19,686. 2022: 52,005 - 20,937 - 6,897 = 24,171. 2021: 42,754 - 17,186 - 5,673 = 19,895. Everything else 2025: 65,011 - 31,681 = 33,330. Keytruda share of sales: 11,084 / 39,121 = 28.3% (2019, continuing basis); 17,186 / 48,704 = 35.3% (2021); 25,011 / 60,115 = 41.6% (2023); 31,681 / 65,011 = 48.7% (2025); Q2 2026 8,366 / 16,607 = 50.4%. Keytruda and Gardasil Q2 2026 (8,366 + 1,169) / 16,607 = 9,535 / 16,607 = 57.4%. Qlex 463 / 8,366 = 5.5%. Keytruda growth: 31,641 / 29,482 - 1 = 7.3% (2025); 29,482 / 25,011 - 1 = 17.9% (2024); 31,641 / 17,186 = 1.84, compound (1.84)^(1/4) - 1 = 16.5% a year; 31,641 / 11,084 = 2.85 (2019-2025). US share of Keytruda 18,829 / 31,641 = 59.5%. International Keytruda 12,812 / 11,610 - 1 = 10.4%; US Keytruda 18,829 / 17,872 - 1 = 5.4%. US Keytruda share of total sales 18,829 / 65,011 = 29.0%. Royalty: 2.5% x 31,681 = 792; 6.5% x 31,681 = 2,059. Gardasil US royalty 7% x 2,641 = 185. Winrevair royalty 22% x 1,443 = 317; 22% x 419 = 92; Winrevair Q2 2026 588 x 4 = 2,352, 22% x 2,352 = 517. Segment margins: Pharmaceutical 45,754 / 58,142 = 78.7% (2025); Q2 2026 11,612 / 14,760 = 78.7% (recast basis). Animal Health 2,131 / 6,354 = 33.5% (2025); 1,938 / 5,877 = 33.0% (2024); 1,737 / 5,625 = 30.9% (2023); 1,963 / 5,550 = 35.4% (2022); 1,950 / 5,568 = 35.0% (2021); Q2 2026 636 / 1,775 = 35.8%. Unallocated research 14,987 / 58,142 = 25.8%; Animal Health research 448 / 6,354 = 7.1%. Animal Health segment profit 2,131 / 45,754 = 4.7% of Pharmaceutical. Gardasil: international 2,592 / 6,158 - 1 = -57.9%; US 2,641 / 2,083 - 1 = 26.8%; share 5,233 / 65,011 = 8.0%; share of sales 2021 5,673 / 48,704 = 11.6%, 2022 6,897 / 59,283 = 11.6%, 2023 8,886 / 60,115 = 14.8%, 2024 8,583 / 64,168 = 13.4%; Q2 2026 1,169 x 4 = 4,676. Vaccines H1 2026 2,314 + 2,361 = 4,675; H1 2025 2,607 + 2,370 = 4,977; 4,675 / 4,977 - 1 = -6.1%. Childhood vaccines growth 2,368 / 2,241 - 1 = 5.7%; 2,485 / 2,368 - 1 = 4.9%; 2,451 / 2,485 - 1 = -1.4%. Pneumococcal: Pneumovax 166 / 893 - 1 = -81%; 825 + 759 + 166 = 1,750; 1,750 / 893 = 2.0; (825 + 759) / 166 = 9.5; Capvaxive + Vaxneuvance 759 + 825 = 1,584; 1,584 / 6,494 = 24.4% of Prevnar. Animal Health: livestock 3,896 / 6,354 = 61.3%; livestock growth 3,300 / 3,295 - 1 = 0.2%, 3,337 / 3,300 - 1 = 1.1%, 3,462 / 3,337 - 1 = 3.7%, 3,896 / 3,462 - 1 = 12.5%; companion 2,458 / 2,415 - 1 = 1.8%, 2,458 / 2,273 - 1 = 8.1%; companion excluding Bravecto 2,458 - 1,100 = 1,358; rest of Animal Health 6,354 - 1,100 = 5,254; Bravecto 359 / 335 - 1 = 7%. Segment 6,354 / 5,877 - 1 = 8.1%; 5,625 / 5,568 - 1 = 1.0%; Q2 2026 1,775 / 1,646 - 1 = 7.8%; compound (6,354 / 5,568)^(1/4) - 1 = 3.4% a year; share 6,354 / 65,011 = 9.8%; 6,354 / 31,681 = 0.20 of Keytruda; 6,354 / 9,467 = 67% of Zoetis; Zoetis 9,467 / 9,256 - 1 = 2.3%. Competitors: Keytruda 31,641 / Opdivo 10,049 = 3.1. Geography: US 36,510 / 65,011 = 56.2%; China 1,939 / 6,802 - 1 = -71%; China share 4,378 / 48,704 = 9.0% (2021), 6,802 / 60,115 = 11.3% (2023), 5,494 / 64,168 = 8.6% (2024), 1,939 / 65,011 = 3.0% (2025); other regions 65,011 - 36,510 - 14,580 - 2,711 - 1,939 = 9,271. Wholesaler receivables 22% + 21% + 13% = 56% (2025); 21 + 21 + 13 = 55 (2024); 21 + 20 + 14 = 55 (2023). Januvia and Janumet: 3,324 + 1,964 = 5,288 (2021); 2,189 + 1,177 = 3,366 (2023); 1,334 + 935 = 2,269 (2024); 1,604 + 940 = 2,544 (2025). Newer products Q2 2026: 588 + 271 + 204 + 184 = 1,247; 1,247 / 8,366 = 14.9%. Bridion 1,841 / 4 = 460 a quarter. Other pharmaceutical Q2 2026 14,760 - 8,366 - 1,169 = 5,225; Q2 2025 14,050 - 7,956 - 1,126 = 4,968; 5,225 / 4,968 - 1 = 5.2%; 2025 share 21,228 / 65,011 = 32.7%. Research: 30,531 / 60,115 = 50.8% of sales (2023). Charges 2026 9.0 + 5.7 = 14.7 bn; per share 3.62 + 2.31 = 5.93. Ohtuvayre 204 x 4 = 816; 12,100 / 816 = 14.8. Tax guidance midpoints (23.5 + 24.5) / 2 = 24.0; (35.0 + 36.0) / 2 = 35.5. Balance sheet: net debt end-2025 2,589 + 46,750 - 14,565 = 34,774; end-2024 2,649 + 34,462 - 13,242 - 447 = 23,422; end-2023 1,372 + 33,683 - 6,841 - 252 = 27,962; 30 June 2026 2,825 + 51,081 - 6,849 - 292 = 46,765, cash and short-term investments 6,849 + 292 = 7,141; net debt to equity 34,774 / 52,606 = 0.66; 46,765 / 41,933 = 1.1. Net income 2023-2025 365 + 17,117 + 18,254 = 35,736. Valuation: year-end 2025 market value 261.26 bn / net income 18.254 bn = 14.3; free cash flow 2025 16,472 - 4,112 = 12,360; 12,360 / 365,090 = 3.4%. Trailing twelve months to June 2026: sales 65,011 - 31,335 + 32,893 = 66,569; net income 18,254 - 9,506 - 5,575 = 3,173. EPS guidance midpoints (5.00 + 5.15) / 2 = 5.075; (5.04 + 5.16) / 2 = 5.10; (2.66 + 2.76) / 2 = 2.71. Protection from 2026: 2043 - 2026 = 17 years; 2028 - 2026 = 2 years. Year-end P/E = market value / net income: 147.55 / 4.442 = 33.2 (2015); 162.31 / 3.920 = 41.4 (2016); 153.30 / 2.394 = 64.0 (2017); 198.69 / 6.220 = 31.9 (2018); 231.56 / 9.843 = 23.5 (2019); 206.96 / 7.067 = 29.3 (2020); 193.59 / 13.049 = 14.8 (2021); 281.30 / 14.519 = 19.4 (2022); 276.26 / 0.365 = 757 (2023); 251.65 / 17.117 = 14.7 (2024); 261.26 / 18.254 = 14.3 (2025); 365.09 / 3.173 = 115.1 (TTM). Return on average equity 2025: 18,254 / ((52,606 + 46,313) / 2) = 18,254 / 49,460 = 36.9%. Gross profit 2025 65,011 - 16,382 = 48,629; 48,629 / 65,011 = 74.8%; royalty 792 / 16,382 = 4.8% of cost of sales. Keytruda increase 2021-2025 31,681 - 17,186 = 14,495; sales increase 65,011 - 48,704 = 16,307. US sales 36,510 / 28,480 - 1 = 28%. Pharmaceutical margin 2021 30,977 / 42,754 = 72.5%. Livestock less companion 3,295 - 2,273 = 1,022 (2021); 3,896 - 2,458 = 1,438 (2025). Prevnar 6,494 / Vaxneuvance 825 = 7.9. Animal Health 2025 6,354 against Keytruda franchise Q2 2026 8,366 - growth rates and changes. — 2015-2026 · publ. September 2026 · source ↗
    Method: Arithmetic on figures reported in Merck's Forms 10-K and 10-Q, results releases, the Bristol Myers Squibb, Pfizer and Zoetis 10-Ks and market data; operands shown in the source line.
  12. ReportedAnimal Health grew slowly.
    Merck & Co. Form 10-K for fiscal 2025 - Animal Health segment: sales by line, Bravecto, segment profit and costs. — FY2025 · publ. 24 February 2026 · source ↗
  13. Moat Explorer calcThe Pharmaceutical segment earned about 78.7% before central research, and Animal Health about 33.5% after its own.
    Moat Explorer calculation from Merck's reported sales, segment and financial statement figures ($ millions unless stated). Lines 2025: Keytruda 31,641 + Keytruda Qlex 40 = 31,681; other pharmaceutical 58,142 - 31,681 - 5,233 = 21,228; Animal Health 6,354; other revenue 515; total 31,681 + 5,233 + 21,228 + 6,354 + 515 = 65,011. 2024: 29,482; 57,400 - 29,482 - 8,583 = 19,335. 2023: 53,583 - 25,011 - 8,886 = 19,686. 2022: 52,005 - 20,937 - 6,897 = 24,171. 2021: 42,754 - 17,186 - 5,673 = 19,895. Everything else 2025: 65,011 - 31,681 = 33,330. Keytruda share of sales: 11,084 / 39,121 = 28.3% (2019, continuing basis); 17,186 / 48,704 = 35.3% (2021); 25,011 / 60,115 = 41.6% (2023); 31,681 / 65,011 = 48.7% (2025); Q2 2026 8,366 / 16,607 = 50.4%. Keytruda and Gardasil Q2 2026 (8,366 + 1,169) / 16,607 = 9,535 / 16,607 = 57.4%. Qlex 463 / 8,366 = 5.5%. Keytruda growth: 31,641 / 29,482 - 1 = 7.3% (2025); 29,482 / 25,011 - 1 = 17.9% (2024); 31,641 / 17,186 = 1.84, compound (1.84)^(1/4) - 1 = 16.5% a year; 31,641 / 11,084 = 2.85 (2019-2025). US share of Keytruda 18,829 / 31,641 = 59.5%. International Keytruda 12,812 / 11,610 - 1 = 10.4%; US Keytruda 18,829 / 17,872 - 1 = 5.4%. US Keytruda share of total sales 18,829 / 65,011 = 29.0%. Royalty: 2.5% x 31,681 = 792; 6.5% x 31,681 = 2,059. Gardasil US royalty 7% x 2,641 = 185. Winrevair royalty 22% x 1,443 = 317; 22% x 419 = 92; Winrevair Q2 2026 588 x 4 = 2,352, 22% x 2,352 = 517. Segment margins: Pharmaceutical 45,754 / 58,142 = 78.7% (2025); Q2 2026 11,612 / 14,760 = 78.7% (recast basis). Animal Health 2,131 / 6,354 = 33.5% (2025); 1,938 / 5,877 = 33.0% (2024); 1,737 / 5,625 = 30.9% (2023); 1,963 / 5,550 = 35.4% (2022); 1,950 / 5,568 = 35.0% (2021); Q2 2026 636 / 1,775 = 35.8%. Unallocated research 14,987 / 58,142 = 25.8%; Animal Health research 448 / 6,354 = 7.1%. Animal Health segment profit 2,131 / 45,754 = 4.7% of Pharmaceutical. Gardasil: international 2,592 / 6,158 - 1 = -57.9%; US 2,641 / 2,083 - 1 = 26.8%; share 5,233 / 65,011 = 8.0%; share of sales 2021 5,673 / 48,704 = 11.6%, 2022 6,897 / 59,283 = 11.6%, 2023 8,886 / 60,115 = 14.8%, 2024 8,583 / 64,168 = 13.4%; Q2 2026 1,169 x 4 = 4,676. Vaccines H1 2026 2,314 + 2,361 = 4,675; H1 2025 2,607 + 2,370 = 4,977; 4,675 / 4,977 - 1 = -6.1%. Childhood vaccines growth 2,368 / 2,241 - 1 = 5.7%; 2,485 / 2,368 - 1 = 4.9%; 2,451 / 2,485 - 1 = -1.4%. Pneumococcal: Pneumovax 166 / 893 - 1 = -81%; 825 + 759 + 166 = 1,750; 1,750 / 893 = 2.0; (825 + 759) / 166 = 9.5; Capvaxive + Vaxneuvance 759 + 825 = 1,584; 1,584 / 6,494 = 24.4% of Prevnar. Animal Health: livestock 3,896 / 6,354 = 61.3%; livestock growth 3,300 / 3,295 - 1 = 0.2%, 3,337 / 3,300 - 1 = 1.1%, 3,462 / 3,337 - 1 = 3.7%, 3,896 / 3,462 - 1 = 12.5%; companion 2,458 / 2,415 - 1 = 1.8%, 2,458 / 2,273 - 1 = 8.1%; companion excluding Bravecto 2,458 - 1,100 = 1,358; rest of Animal Health 6,354 - 1,100 = 5,254; Bravecto 359 / 335 - 1 = 7%. Segment 6,354 / 5,877 - 1 = 8.1%; 5,625 / 5,568 - 1 = 1.0%; Q2 2026 1,775 / 1,646 - 1 = 7.8%; compound (6,354 / 5,568)^(1/4) - 1 = 3.4% a year; share 6,354 / 65,011 = 9.8%; 6,354 / 31,681 = 0.20 of Keytruda; 6,354 / 9,467 = 67% of Zoetis; Zoetis 9,467 / 9,256 - 1 = 2.3%. Competitors: Keytruda 31,641 / Opdivo 10,049 = 3.1. Geography: US 36,510 / 65,011 = 56.2%; China 1,939 / 6,802 - 1 = -71%; China share 4,378 / 48,704 = 9.0% (2021), 6,802 / 60,115 = 11.3% (2023), 5,494 / 64,168 = 8.6% (2024), 1,939 / 65,011 = 3.0% (2025); other regions 65,011 - 36,510 - 14,580 - 2,711 - 1,939 = 9,271. Wholesaler receivables 22% + 21% + 13% = 56% (2025); 21 + 21 + 13 = 55 (2024); 21 + 20 + 14 = 55 (2023). Januvia and Janumet: 3,324 + 1,964 = 5,288 (2021); 2,189 + 1,177 = 3,366 (2023); 1,334 + 935 = 2,269 (2024); 1,604 + 940 = 2,544 (2025). Newer products Q2 2026: 588 + 271 + 204 + 184 = 1,247; 1,247 / 8,366 = 14.9%. Bridion 1,841 / 4 = 460 a quarter. Other pharmaceutical Q2 2026 14,760 - 8,366 - 1,169 = 5,225; Q2 2025 14,050 - 7,956 - 1,126 = 4,968; 5,225 / 4,968 - 1 = 5.2%; 2025 share 21,228 / 65,011 = 32.7%. Research: 30,531 / 60,115 = 50.8% of sales (2023). Charges 2026 9.0 + 5.7 = 14.7 bn; per share 3.62 + 2.31 = 5.93. Ohtuvayre 204 x 4 = 816; 12,100 / 816 = 14.8. Tax guidance midpoints (23.5 + 24.5) / 2 = 24.0; (35.0 + 36.0) / 2 = 35.5. Balance sheet: net debt end-2025 2,589 + 46,750 - 14,565 = 34,774; end-2024 2,649 + 34,462 - 13,242 - 447 = 23,422; end-2023 1,372 + 33,683 - 6,841 - 252 = 27,962; 30 June 2026 2,825 + 51,081 - 6,849 - 292 = 46,765, cash and short-term investments 6,849 + 292 = 7,141; net debt to equity 34,774 / 52,606 = 0.66; 46,765 / 41,933 = 1.1. Net income 2023-2025 365 + 17,117 + 18,254 = 35,736. Valuation: year-end 2025 market value 261.26 bn / net income 18.254 bn = 14.3; free cash flow 2025 16,472 - 4,112 = 12,360; 12,360 / 365,090 = 3.4%. Trailing twelve months to June 2026: sales 65,011 - 31,335 + 32,893 = 66,569; net income 18,254 - 9,506 - 5,575 = 3,173. EPS guidance midpoints (5.00 + 5.15) / 2 = 5.075; (5.04 + 5.16) / 2 = 5.10; (2.66 + 2.76) / 2 = 2.71. Protection from 2026: 2043 - 2026 = 17 years; 2028 - 2026 = 2 years. Year-end P/E = market value / net income: 147.55 / 4.442 = 33.2 (2015); 162.31 / 3.920 = 41.4 (2016); 153.30 / 2.394 = 64.0 (2017); 198.69 / 6.220 = 31.9 (2018); 231.56 / 9.843 = 23.5 (2019); 206.96 / 7.067 = 29.3 (2020); 193.59 / 13.049 = 14.8 (2021); 281.30 / 14.519 = 19.4 (2022); 276.26 / 0.365 = 757 (2023); 251.65 / 17.117 = 14.7 (2024); 261.26 / 18.254 = 14.3 (2025); 365.09 / 3.173 = 115.1 (TTM). Return on average equity 2025: 18,254 / ((52,606 + 46,313) / 2) = 18,254 / 49,460 = 36.9%. Gross profit 2025 65,011 - 16,382 = 48,629; 48,629 / 65,011 = 74.8%; royalty 792 / 16,382 = 4.8% of cost of sales. Keytruda increase 2021-2025 31,681 - 17,186 = 14,495; sales increase 65,011 - 48,704 = 16,307. US sales 36,510 / 28,480 - 1 = 28%. Pharmaceutical margin 2021 30,977 / 42,754 = 72.5%. Livestock less companion 3,295 - 2,273 = 1,022 (2021); 3,896 - 2,458 = 1,438 (2025). Prevnar 6,494 / Vaxneuvance 825 = 7.9. Animal Health 2025 6,354 against Keytruda franchise Q2 2026 8,366 - product and segment totals, growth and royalties. — 2015-2026 · publ. September 2026 · source ↗
    Method: Arithmetic on figures reported in Merck's Forms 10-K and 10-Q, results releases, the Bristol Myers Squibb, Pfizer and Zoetis 10-Ks and market data; operands shown in the source line.
  14. ReportedKeytruda sold $18,829 million in the United States and $12,812 million elsewhere in 2025; Gardasil, after China, was split almost evenly, $2,641 million American and $2,592 million international.
    Merck & Co. Form 10-K for fiscal 2025 - vaccines and China: Gardasil, the childhood and pneumococcal vaccines, and sales in China. — FY2025 · publ. 24 February 2026 · source ↗
  15. ReportedKeytruda sold $18,829 million in the United States and $12,812 million elsewhere in 2025; Gardasil, after China, was split almost evenly, $2,641 million American and $2,592 million international.
    Merck & Co. Form 10-K for fiscal 2025 - vaccines and China: Gardasil, the childhood and pneumococcal vaccines, and sales in China. — FY2025 · publ. 24 February 2026 · source ↗
  16. ReportedMerck's American sales grew 13% to $36.5 billion in 2025, while international sales fell from 50% of the total to 44%, so every line is becoming more dependent on the American payers who will set Keytruda's price in 2029.
    Merck & Co. Form 10-K for fiscal 2025 - Item 7 MD&A and product sales note: sales by product, segment and country. — FY2025 · publ. 24 February 2026 · source ↗
  17. ReportedMerck's American sales grew 13% to $36.5 billion in 2025, while international sales fell from 50% of the total to 44%, so every line is becoming more dependent on the American payers who will set Keytruda's price in 2029.
    Merck & Co. Form 10-K for fiscal 2025 - Item 7 MD&A and product sales note: sales by product, segment and country. — FY2025 · publ. 24 February 2026 · source ↗
  18. ReportedKeytruda, Gardasil and the other human products all sit in one Pharmaceutical segment, which earned $45,754 million of segment profit in 2025, while the $14,987 million of central research that supports them is left unallocated.
    Merck & Co. Form 10-K for fiscal 2025 - financial statements and notes: earnings, cash flow, balance sheet, acquisitions, research and segment profit. — FY2025 · publ. 24 February 2026 · source ↗
  19. ReportedKeytruda, Gardasil and the other human products all sit in one Pharmaceutical segment, which earned $45,754 million of segment profit in 2025, while the $14,987 million of central research that supports them is left unallocated.
    Merck & Co. Form 10-K for fiscal 2025 - financial statements and notes: earnings, cash flow, balance sheet, acquisitions, research and segment profit. — FY2025 · publ. 24 February 2026 · source ↗
  20. Moat Explorer calcKeytruda and Gardasil together were about 57.4% of sales in the second quarter of 2026; a share that keeps rising toward 2028 would mean Merck is heading into its patent dates more concentrated, not less.
    Moat Explorer calculation from Merck's reported sales, segment and financial statement figures ($ millions unless stated). Lines 2025: Keytruda 31,641 + Keytruda Qlex 40 = 31,681; other pharmaceutical 58,142 - 31,681 - 5,233 = 21,228; Animal Health 6,354; other revenue 515; total 31,681 + 5,233 + 21,228 + 6,354 + 515 = 65,011. 2024: 29,482; 57,400 - 29,482 - 8,583 = 19,335. 2023: 53,583 - 25,011 - 8,886 = 19,686. 2022: 52,005 - 20,937 - 6,897 = 24,171. 2021: 42,754 - 17,186 - 5,673 = 19,895. Everything else 2025: 65,011 - 31,681 = 33,330. Keytruda share of sales: 11,084 / 39,121 = 28.3% (2019, continuing basis); 17,186 / 48,704 = 35.3% (2021); 25,011 / 60,115 = 41.6% (2023); 31,681 / 65,011 = 48.7% (2025); Q2 2026 8,366 / 16,607 = 50.4%. Keytruda and Gardasil Q2 2026 (8,366 + 1,169) / 16,607 = 9,535 / 16,607 = 57.4%. Qlex 463 / 8,366 = 5.5%. Keytruda growth: 31,641 / 29,482 - 1 = 7.3% (2025); 29,482 / 25,011 - 1 = 17.9% (2024); 31,641 / 17,186 = 1.84, compound (1.84)^(1/4) - 1 = 16.5% a year; 31,641 / 11,084 = 2.85 (2019-2025). US share of Keytruda 18,829 / 31,641 = 59.5%. International Keytruda 12,812 / 11,610 - 1 = 10.4%; US Keytruda 18,829 / 17,872 - 1 = 5.4%. US Keytruda share of total sales 18,829 / 65,011 = 29.0%. Royalty: 2.5% x 31,681 = 792; 6.5% x 31,681 = 2,059. Gardasil US royalty 7% x 2,641 = 185. Winrevair royalty 22% x 1,443 = 317; 22% x 419 = 92; Winrevair Q2 2026 588 x 4 = 2,352, 22% x 2,352 = 517. Segment margins: Pharmaceutical 45,754 / 58,142 = 78.7% (2025); Q2 2026 11,612 / 14,760 = 78.7% (recast basis). Animal Health 2,131 / 6,354 = 33.5% (2025); 1,938 / 5,877 = 33.0% (2024); 1,737 / 5,625 = 30.9% (2023); 1,963 / 5,550 = 35.4% (2022); 1,950 / 5,568 = 35.0% (2021); Q2 2026 636 / 1,775 = 35.8%. Unallocated research 14,987 / 58,142 = 25.8%; Animal Health research 448 / 6,354 = 7.1%. Animal Health segment profit 2,131 / 45,754 = 4.7% of Pharmaceutical. Gardasil: international 2,592 / 6,158 - 1 = -57.9%; US 2,641 / 2,083 - 1 = 26.8%; share 5,233 / 65,011 = 8.0%; share of sales 2021 5,673 / 48,704 = 11.6%, 2022 6,897 / 59,283 = 11.6%, 2023 8,886 / 60,115 = 14.8%, 2024 8,583 / 64,168 = 13.4%; Q2 2026 1,169 x 4 = 4,676. Vaccines H1 2026 2,314 + 2,361 = 4,675; H1 2025 2,607 + 2,370 = 4,977; 4,675 / 4,977 - 1 = -6.1%. Childhood vaccines growth 2,368 / 2,241 - 1 = 5.7%; 2,485 / 2,368 - 1 = 4.9%; 2,451 / 2,485 - 1 = -1.4%. Pneumococcal: Pneumovax 166 / 893 - 1 = -81%; 825 + 759 + 166 = 1,750; 1,750 / 893 = 2.0; (825 + 759) / 166 = 9.5; Capvaxive + Vaxneuvance 759 + 825 = 1,584; 1,584 / 6,494 = 24.4% of Prevnar. Animal Health: livestock 3,896 / 6,354 = 61.3%; livestock growth 3,300 / 3,295 - 1 = 0.2%, 3,337 / 3,300 - 1 = 1.1%, 3,462 / 3,337 - 1 = 3.7%, 3,896 / 3,462 - 1 = 12.5%; companion 2,458 / 2,415 - 1 = 1.8%, 2,458 / 2,273 - 1 = 8.1%; companion excluding Bravecto 2,458 - 1,100 = 1,358; rest of Animal Health 6,354 - 1,100 = 5,254; Bravecto 359 / 335 - 1 = 7%. Segment 6,354 / 5,877 - 1 = 8.1%; 5,625 / 5,568 - 1 = 1.0%; Q2 2026 1,775 / 1,646 - 1 = 7.8%; compound (6,354 / 5,568)^(1/4) - 1 = 3.4% a year; share 6,354 / 65,011 = 9.8%; 6,354 / 31,681 = 0.20 of Keytruda; 6,354 / 9,467 = 67% of Zoetis; Zoetis 9,467 / 9,256 - 1 = 2.3%. Competitors: Keytruda 31,641 / Opdivo 10,049 = 3.1. Geography: US 36,510 / 65,011 = 56.2%; China 1,939 / 6,802 - 1 = -71%; China share 4,378 / 48,704 = 9.0% (2021), 6,802 / 60,115 = 11.3% (2023), 5,494 / 64,168 = 8.6% (2024), 1,939 / 65,011 = 3.0% (2025); other regions 65,011 - 36,510 - 14,580 - 2,711 - 1,939 = 9,271. Wholesaler receivables 22% + 21% + 13% = 56% (2025); 21 + 21 + 13 = 55 (2024); 21 + 20 + 14 = 55 (2023). Januvia and Janumet: 3,324 + 1,964 = 5,288 (2021); 2,189 + 1,177 = 3,366 (2023); 1,334 + 935 = 2,269 (2024); 1,604 + 940 = 2,544 (2025). Newer products Q2 2026: 588 + 271 + 204 + 184 = 1,247; 1,247 / 8,366 = 14.9%. Bridion 1,841 / 4 = 460 a quarter. Other pharmaceutical Q2 2026 14,760 - 8,366 - 1,169 = 5,225; Q2 2025 14,050 - 7,956 - 1,126 = 4,968; 5,225 / 4,968 - 1 = 5.2%; 2025 share 21,228 / 65,011 = 32.7%. Research: 30,531 / 60,115 = 50.8% of sales (2023). Charges 2026 9.0 + 5.7 = 14.7 bn; per share 3.62 + 2.31 = 5.93. Ohtuvayre 204 x 4 = 816; 12,100 / 816 = 14.8. Tax guidance midpoints (23.5 + 24.5) / 2 = 24.0; (35.0 + 36.0) / 2 = 35.5. Balance sheet: net debt end-2025 2,589 + 46,750 - 14,565 = 34,774; end-2024 2,649 + 34,462 - 13,242 - 447 = 23,422; end-2023 1,372 + 33,683 - 6,841 - 252 = 27,962; 30 June 2026 2,825 + 51,081 - 6,849 - 292 = 46,765, cash and short-term investments 6,849 + 292 = 7,141; net debt to equity 34,774 / 52,606 = 0.66; 46,765 / 41,933 = 1.1. Net income 2023-2025 365 + 17,117 + 18,254 = 35,736. Valuation: year-end 2025 market value 261.26 bn / net income 18.254 bn = 14.3; free cash flow 2025 16,472 - 4,112 = 12,360; 12,360 / 365,090 = 3.4%. Trailing twelve months to June 2026: sales 65,011 - 31,335 + 32,893 = 66,569; net income 18,254 - 9,506 - 5,575 = 3,173. EPS guidance midpoints (5.00 + 5.15) / 2 = 5.075; (5.04 + 5.16) / 2 = 5.10; (2.66 + 2.76) / 2 = 2.71. Protection from 2026: 2043 - 2026 = 17 years; 2028 - 2026 = 2 years. Year-end P/E = market value / net income: 147.55 / 4.442 = 33.2 (2015); 162.31 / 3.920 = 41.4 (2016); 153.30 / 2.394 = 64.0 (2017); 198.69 / 6.220 = 31.9 (2018); 231.56 / 9.843 = 23.5 (2019); 206.96 / 7.067 = 29.3 (2020); 193.59 / 13.049 = 14.8 (2021); 281.30 / 14.519 = 19.4 (2022); 276.26 / 0.365 = 757 (2023); 251.65 / 17.117 = 14.7 (2024); 261.26 / 18.254 = 14.3 (2025); 365.09 / 3.173 = 115.1 (TTM). Return on average equity 2025: 18,254 / ((52,606 + 46,313) / 2) = 18,254 / 49,460 = 36.9%. Gross profit 2025 65,011 - 16,382 = 48,629; 48,629 / 65,011 = 74.8%; royalty 792 / 16,382 = 4.8% of cost of sales. Keytruda increase 2021-2025 31,681 - 17,186 = 14,495; sales increase 65,011 - 48,704 = 16,307. US sales 36,510 / 28,480 - 1 = 28%. Pharmaceutical margin 2021 30,977 / 42,754 = 72.5%. Livestock less companion 3,295 - 2,273 = 1,022 (2021); 3,896 - 2,458 = 1,438 (2025). Prevnar 6,494 / Vaxneuvance 825 = 7.9. Animal Health 2025 6,354 against Keytruda franchise Q2 2026 8,366 - revenue mix, concentration and geography. — 2015-2026 · publ. September 2026 · source ↗
    Method: Arithmetic on figures reported in Merck's Forms 10-K and 10-Q, results releases, the Bristol Myers Squibb, Pfizer and Zoetis 10-Ks and market data; operands shown in the source line.
Sources
Generated September 25, 2026