The control of both endogenous and exogenous labile metal ions in biological systems has important implications in the field of medicine. In this presentation, we will discuss our efforts to harness labile ions in order to control their downstream biological effects. The first part of this presentation will describe small molecules that can modulate mitochondrial calcium uptake. By controlling mitochondrial calcium uptake, these compounds can preserve viability under conditions of cellular stress. In the second part of this presentation, efforts to control the localization and biodistribution of exogenous labile radioactive metal ions will be discussed in the context of nuclear medicine applications.