Her research focuses on understanding molecular mechanisms behind diseases with genetic and acquired mitochondrial abnormalities. Her ultimate goal is to develop novel mitochondrial activating treatments and she is currently investigating vitamin B3 as a mitochondrial booster.
She received her PhD in Molecular Medicine at the University of Eastern Finland in 2009, worked in  Switzerland for four years and in 2015 came back to run her own laboratory at the University of Helsinki, when she received the prestigious Academy Research Fellowship.

The focus of Eija Pirinen research is to investigate molecular mechanisms behind diseases characterized with genetic or acquired mitochondria dysfunction such as inherited mitochondrial disorders, obesity and type 2 diabetes.