Herein is the first reported conceptual density functional theory (DFT) investigation of the purine alkaloid theacrine and the comparison of quantum chemical properties to the closely related stimulant caffeine. DFT global chemical reactivity descriptors (chemical hardness/softness, chemical potential/ electronegativity, and electrophilicity) and local reactivity descriptors (Fukui functions and dual descriptor) were calculated for both compounds using Spartan ‘16 software. All calculations were carried out at the B3LYP/6-31G* level of theory. Reactivity analysis of the Fukui dual descriptor calculations reveals sites of nucleophilic and electrophilic attack. The results provide a solid chemical foundation for understanding how theacrine interacts with cellular systems.