German chemical and pharmaceutical company.
Founded in 1863 by Friedrich Bayer (1825–1880), it now operates plants in more than 30 countries. Bayer has originated scores of pharmaceuticals, chemicals, and synthetic materials; it was the first developer and marketer of aspirin (1899); of Prontosil, the first sulfa drug (1935); and of polyurethane (1937). Bayer was part of the chemical cartel IG Farben from 1925 to 1945, when the latter was dissolved by the Allies; it was reestablished as an independent company in 1951. Its most noteworthy drug of the 1990s was the antibiotic Cipro. Its headquarters are in Leverkusen.