Jansen received her doctoral degree from the University of Groningen (The Netherlands) in 1995, studying computational medicinal chemistry. Her dissertation topic concerned 3D modeling of the melatonin receptor, including work on synthesizing and separating analytes to probe its chemistry. She completed a postdoctoral fellowship at Uppsala University in 1997. Her work there related to modeling receptor interactions of drug leads to judge their serotonergic or dopaminergic activities.