In 1922 Heymans became Lecturer in Pharmacodynamics at Ghent University, and in 1930 succeeded his father, Jean-François Heymans, as Professor of Pharmacology, as well as being appointed Head of the Department of Pharmacology, Pharmacodynamics, and Toxicology; and Director of the J. F. Heymans Institute.
I 1922 blev Heymans blev lektor i farmakodynamik på Gent universitet, og i 1930 efterfulgte han sin far, Jean-François Heymans, som professor i farmakologi, såvel som at blive udnævnt til leder af Institut for farmakologi, farmakodynamik og toksikologi; og direktør for J. F. Heymans Institut.