Sanofi is the heir to a long history that includes some of the major scientific advances of the nineteenth and twentieth centuries, and the reputations of major industrial laboratories in the development of chemistry, pharmacy and medicine. 
  
In 1718, Laboratoires Midy was founded by a family of pharmacists. In 1980, the Clin Midy group was acquired by Sanofi.

Laboratoires Dausse was founded in 1834 and is Laboratoires Robert & Carrière in 1901. They merged to create Synthélabo in 1970.

In 1860 the pharmacist Etienne Poulenc created Wittmann et Poulenc Jeune. And in 1910 it was Rorer’s turn. The two companies eventually merged to form Rhône-Poulenc Rorer in 1990.

In 1863, a group of chemists, sales people and workers embarked on the manufacture of dyes in a small factory to the west of the town of Höchst in Germany. This was the origin of the company Hoechst, which merged with Roussel (founded in 1911) to form Hoechst Marion Roussel.

In 1887, Marcel Mérieux, a student of Louis Pasteur, founds the Mérieux Biological Institute which, in 2004 became Sanofi Pasteur, the Sanofi’s vaccine division.

The two young groups Sanofi and Synthélabo merged in May 1999 to create a major new pharmaceutical player. Sanofi dates back to 1973 and Synthélabo to 1970.

In December 1999, Rhône-Poulenc and Hoechst Marion Roussel formalized their merger with the creation of the Franco-German group Aventis, one of the world’s largest pharmaceutical companies.

In August 2004, Sanofi-Synthelabo acquired Aventis. The takeover was finalized on December 31 of that year, giving birth to sanofi-aventis.

On May 6, 2011, sanofi-aventis simplified its name to Sanofi.”