SanofiSynthelabo

Sanofi-Synthelabo, commonly written Sanofi-Synthelabo, was a French multinational pharmaceutical company created in 2004 by the merger of Sanofi S.A. and Synthélabo (Synthelabo). It emerged as one of the world's largest pharmaceutical groups, with activities spanning prescription medicines, vaccines, and consumer healthcare products, and a global footprint in research, development, manufacturing, and marketing.

In 2004, Sanofi-Synthelabo merged with Aventis to form Sanofi-Aventis, a transaction that consolidated a significant portion of the global pharmaceutical industry. The combined group retained Paris as its headquarters and operated through major business units, including Sanofi Pasteur, the vaccines division.

Under Sanofi-Synthelabo branding, the company pursued growth through internal development and external collaborations, with a broad portfolio across therapeutic areas such as diabetes, cardiovascular disease, oncology, infectious diseases, and immunology. It also pursued investments in vaccines, consumer health care, and specialty medicines.

In 2011, the company adopted the simplified name Sanofi in most markets, with Sanofi-Synthelabo as a historical reference within the broader corporate lineage of the modern Sanofi. The Sanofi-Synthelabo era is thus viewed as the transitional period that led to the current Sanofi organization.