ABSTRACT Herein, we present deuterated azobenzene photoswitches as a general means of enhancing photopharmacological molecules. Deuteration can improve azobenzene performance in terms of light sensitivity, photoswitch efficiency, and photoswitch kinetics with minimal alteration to the underlying structure of the photopharmacological ligand. We report synthesized deuterated azobenzene-based ligands for the optimized optical control of ion channel and G protein-coupled receptor function in live cells, setting the stage for the straightforward, widespread adoption of this approach.