Almost a century ago, the first insulin was produced by Banting, Best, MacLeod and Collip in Toronto, thereby enabling life-saving treatment for people with diabetes. Since then, there have been many advancements in insulin production and development of new insulin analogues. In this article, we reflect on the rich heritage of Sanofi and its predecessor, Hoechst, in insulin production and development, from being one of the first companies to produce insulin in Europe in 1923, to modern-day insulin analogues and integrated care solutions at present-day Sanofi.