How Merck Makes its Money: Revenue Breakdown

How Does Merck Make its Money?

Merck is one of the world’s largest pharmaceutical companies and the maker of Keytruda, the best-selling drug in the world. Keytruda is a cancer immunotherapy (PD-1 inhibitor) approved for over 40 different cancer types, including lung cancer, melanoma, head and neck cancer, and bladder cancer. It alone generates nearly half of Merck’s total revenue — an extraordinary concentration for a company of this size.

Beyond Keytruda, Merck operates across oncology, vaccines (including Gardasil, the HPV vaccine), cardiovascular, diabetes, and animal health. The company also recently launched Winrevair for pulmonary arterial hypertension and acquired Prometheus Biosciences ($10.8B) for its IBD drug candidate. These moves are part of Merck’s aggressive diversification efforts ahead of Keytruda’s 2028 patent expiration, which represents the defining strategic challenge for the company.

Merck (MRK) Business Model

Merck operates in the pharmaceuticals sector with two main divisions: Pharmaceutical (human health drugs and vaccines) and Animal Health (Merck Animal Health, one of the largest veterinary pharma businesses globally). This breakdown uses data from Merck’s 2024 fiscal year filings with the SEC.

The pharmaceutical industry business model involves enormous upfront R&D investment ($13.6B in R&D spend in 2024), patent-protected pricing during exclusivity periods, and eventual generic erosion. Merck’s scale allows it to run dozens of simultaneous clinical trials and target the most lucrative therapeutic areas. The company deploys a global commercial infrastructure that reaches healthcare providers in over 140 countries.

Merck Competitors

Merck’s key competitors and comparable public companies in the pharmaceuticals sector include Eli Lilly, Pfizer, Johnson & Johnson, and Amgen. Each of these companies competes for market share, investor attention, and revenue in overlapping segments. See how Merck stacks up by comparing their revenue breakdown, margins, and growth metrics.

Revenue Breakdown

Keytruda — 46% of Revenue

Keytruda ($29.5B) is the single most important product for Merck, growing 18% and now the highest-revenue drug globally. The drug works by blocking the PD-1 protein, allowing the immune system to attack cancer cells. Keytruda has been approved in an extraordinary number of indications — more than any other cancer immunotherapy — and continues to expand into earlier-stage cancers and new combinations.

Keytruda’s growth was driven by expanded use in adjuvant (post-surgery prevention) settings and new combination regimens. However, Keytruda’s U.S. patent expires in 2028, which will trigger biosimilar competition and significant revenue erosion. Finding ways to extend Keytruda’s lifecycle (through subcutaneous formulations, new combinations, and next-generation variants) is Merck’s top priority.

Gardasil — 9% of Revenue

Gardasil ($5.6B) is the world’s leading HPV vaccine, protecting against the human papillomavirus that causes cervical cancer and other cancers. Revenue plunged 37.1% due to China inventory destocking — Chinese distributors had built up excess inventory that took quarters to work through. Excluding the China disruption, underlying Gardasil demand remained solid as more countries add HPV vaccination to their national immunization programs.

Animal Health — 9% of Revenue

Merck Animal Health ($5.6B) is the world’s #2 veterinary pharmaceutical company (behind Zoetis). Products include vaccines, anti-parasitics, and specialty therapeutics for livestock and companion animals. Revenue was flat in 2024, but the long-term trend benefits from rising global protein consumption and increasing pet healthcare spending.

Other Pharmaceuticals — 33% of Revenue

This category ($21B) includes Merck’s growing portfolio of newer drugs: Winrevair (pulmonary arterial hypertension, launched 2024), Welireg (renal cell carcinoma), Lynparza (ovarian/breast cancer, partnered with AstraZeneca), Bridion (neuromuscular blockade reversal), and many others. This category surged 33.8%, driven by new launch contributions and growth in established products. Diversifying this portfolio is critical to offsetting the eventual Keytruda cliff.

Merck (MRK) Income Statement

Financial data sourced from Merck SEC Filings.

Merck (MRK) Key Financial Metrics

• Gross Margin: 67.8% — Strong pharma margins reflecting the pricing power of patented drugs. Keytruda’s gross margin is estimated at 90%+, while Animal Health and older generics-exposed products pull the blended margin down.
• Operating Margin: 25.1% — Healthy, though lower than some pure-play pharma peers because Merck invests ~21% of revenue in R&D ($13.6B), one of the largest R&D budgets in the industry.
• Revenue Growth: 6.8% — Solid growth driven by Keytruda’s continued expansion, partially offset by Gardasil’s China-related decline and Lagevrio’s wind-down.

Is Merck Profitable?

Yes, Merck is highly profitable, reporting $13.2B in net income on $64.2B in revenue. The dramatic increase from just $300M in net income in 2023 reflects the prior year being depressed by large acquisition-related charges (the Prometheus Biosciences deal). On an adjusted basis, Merck has been consistently profitable for decades, generating strong free cash flow that funds its aggressive M&A strategy, large R&D pipeline, and one of the highest dividend payouts in pharma (~$8B annually).

Merck (MRK): What to Watch

1. 2028 Keytruda patent cliff — This is the defining event for Merck. With Keytruda generating $29.5B (46% of revenue), even partial biosimilar erosion in 2029+ would create a revenue hole of $10B+. Merck’s subcutaneous formulation and next-gen PD-1 strategies aim to extend the franchise.
2. Winrevair launch trajectory — Launched in 2024 for pulmonary arterial hypertension, Winrevair is expected to become a multi-billion dollar drug. Early adoption trends and peak sales estimates are closely watched by analysts.
3. Gardasil China recovery — Gardasil’s 37% decline was driven by inventory issues, not underlying demand. A full recovery in China would add $2-3B back to the top line.
4. M&A pipeline — Merck needs to acquire or develop multiple blockbuster drugs to fill the Keytruda gap. The quality and pricing of future acquisitions will determine whether Merck can maintain its revenue base through the patent cliff.
5. ADC (antibody-drug conjugate) pipeline — Merck is investing heavily in next-generation cancer therapies including ADCs and bispecific antibodies. Clinical trial results from these programs could define Merck’s oncology future beyond Keytruda.

Merck (MRK) Financial Summary

Merck (MRK) is a global pharmaceutical company that generated $64.2B in total revenue in fiscal year 2024, growing 6.8% year-over-year. Keytruda, the world’s best-selling drug, contributed $29.5B. The company earned $13.2B in net income while investing aggressively to diversify ahead of Keytruda’s 2028 patent expiration. For a deeper look at Merck’s revenue breakdown, business segments, and financial performance, review the detailed analysis above.