Sanofi S.A. is a French multinational pharmaceutical company headquartered in Paris, France, as of 2013 the world's fifth-largest by prescription sales.[3] Originally, the company was formed in 1973 and the current incarnation was formed as Sanofi-Aventis in 2004, by the merger of Aventis and Sanofi-Synthélabo, which were each the product of several previous mergers. It changed its name to Sanofi in May 2011. The company is a component of the Euro Stoxx 50 stock market index.[4]

Sanofi engages in the research and development, manufacturing and marketing of pharmaceutical drugs principally in the prescription market, but the firm also develops over-the-counter medication. The company covers seven major therapeutic areas: cardiovascular, central nervous system, diabetes, internal medicine, oncology, thrombosis and vaccines (it is the world's largest producer of the latter through its subsidiary Sanofi Pasteur).