Merck & Co.

Merck & Co., Inc. was founded in the United States on January 1, 1891, when 23-year-old George Merck established a business to distribute fine chemicals in New York City and nearby areas. The company’s official timeline records the first Merck Manual in 1899, the creation of the Merck Research Laboratory in Rahway in 1933, and the 1953 merger with Sharp & Dohme, which combined chemical research and manufacturing with pharmaceutical development and international reach. [1]

Merck’s current fact sheet identifies it as Merck in the United States and Canada and MSD elsewhere. As of December 31, 2025, it reported approximately 75,000 employees, headquarters in Rahway, New Jersey, and three businesses: pharmaceuticals, vaccines, and animal health. The same fact sheet reports 2025 revenue of $65.0 billion and research-and-development expense of $15.8 billion. [2]

The 2025 Form 10-K shows how that portfolio translates into current operations: Keytruda/Keytruda Qlex generated $31.680 billion in 2025 sales, Gardasil/Gardasil 9 generated $5.233 billion, and Animal Health generated $6.354 billion. The filing describes oncology, vaccines, cardiometabolic and respiratory medicines, diabetes, immunology, virology, and animal health as major franchises, while noting that product performance varied across them during the year. [3]