Merck & Co.

Merck & Co., Inc. is an American multinational pharmaceutical company headquartered in Rahway, New Jersey. The company does business as Merck Sharp & Dohme or MSD outside the United States and Canada. The company is ranked fourth on the list of largest biomedical companies by revenue.

The company's revenues are primarily from cancer treatments, vaccines, and animal health products. In 2024, 46% of the company's revenue, or $29.5 billion, came from sales of Keytruda (pembrolizumab), a PD-1 inhibitor used to treat various types of cancers, and 13% of the company's revenue, or $8.6 billion, came from sales of Gardasil, an HPV vaccine. In addition, 9% of the company's revenue, or $5.8 billion, came from the sales of animal health products.

The company is ranked 65th on the Fortune 500 and 76th on the Forbes Global 2000.

In 1891, Merck & Co. was established as the American affiliate of Merck Group, founded by the Merck family, and the companies are still in trademark disputes in several countries over the right to use the name "Merck".

Merck & Co. traces its origins to its former German parent company Merck Group, which was established by the Merck family in 1668 when Friedrich Jacob Merck purchased a pharmacy in Darmstadt. In 1827, Merck Group evolved from a pharmacy to a drug manufacturer company with the commercial manufacture of morphine. Merck perfected the chemical process of deriving morphine from opium and later introduced cocaine, used to treat sinus problems and to add to beverages to boost energy levels.

In 1887 a German-born, long-time Merck employee, Theodore Weicker, went to the United States to represent Merck Group. In 1891, with $200,000 received from E. Merck, Weicker started Merck & Co., with headquarters in lower Manhattan. That year George Merck, the 23-year-old son of the then head of E. Merck (and grandson of the founder) joined Weicker in New York. Merck & Co. operated from 1891 to 1917 as the US subsidiary of the Merck Group.

After the U.S. entered World War I, due to its German connections, Merck & Co. was the subject of expropriation under the Trading with the Enemy Act of 1917. The government seized 80 percent of the shares owned by the German parent company and sold it. In 1919, George F. Merck (head of the American branch of the Merck family), in partnership with Goldman Sachs and Lehman Brothers, bought the company back at a U.S. government auction for $3.5 million, but Merck & Co. remained a separate company from its former German parent. Merck & Co. holds the trademark rights to the "Merck" name in the United States and Canada, while its former parent company retains the rights in the rest of the world; the right to use the Merck name was the subject of litigation between the two companies in 2016.

In 1925, George W. Merck succeeded his father George F. Merck as president. In 1927, the corporation merged with the Powers-Weightman-Rosengarten Company, a Philadelphia quinine manufacturer. George Merck remained president and Frederic Rosengarten became chairman of the board. In 1929, H. K. Mulford Company merged with Sharp and Dohme, Inc. and brought vaccine technology, including immunization of cavalry horses in World War I and delivery of a diphtheria antitoxin to Merck & Co.