Two terms common to aqueous supramolecular chemistry are the Hydrophobic Effect (the phenomenon whereby oil and water don’t mix), and the Hofmeister Effect (most succinctly put as how salts affect the solubility of organic solutes). Correspondingly, both phenomena are of immense importance to the biological realm where they control biomolecule structure and function, and medicinal chemistry where they modulate drug delivery and binding. A key facet of our research is to probe how salts and neutrals affect the properties of proteins. Our viewpoint is that proteins are exceptionally large and complex hosts that bind a wide range of guests weakly. Such interactions are commonly described as “non-specific”, but our studies using 2D/3D heteronuclear NMR spectroscopy, differential scanning calorimetry (DSC), dynamic and static light scattering (DLS and SLS), and CD spectroscopy frequently reveal specific co-solute binding that specifically influence protein stability and aggregation. By these studies we hope to be able to map out the important factors responsible for the great variety in physical properties observed in proteins.