1,4-Dihydro-1-methyl-4-oxo-3-pyridinecarboxamide-d3 is the isotope labelled analog of 1,4-Dihydro-1-methyl-4-oxo-3-pyridinecarboxamide (D453415); a compound that has been shown to be one of the potential novel biomarkers of peroxisome proliferation in the rat.