Bayer AG (German, pronounce [ˈbaɪə]) (ISIN: DE0005752000, TYO: 4863) is a German chemical and pharmaceutical company founded in Barmen, Germany in 1863. Today it is headquartered in Leverkusen, North Rhine-Westphalia, Germany. It is well-known for its original brand of aspirin. Bayer is currently the third largest pharmaceutical company in the world.