The modification of biomolecules, small molecules, and other agents of via conjugation of excipients, tags, or labels is of great importance. For example, the modification of therapeutic agents can confer improved stability, solubility, duration of action, or pharmacological properties. Supramolecular chemistry utilizes specific, directional, reversible, non-covalent molecular recognition motifs in order to achieve organization of molecules, and can be used to complex tags to agents of interest (e.g., insulin, glucagon, antibodies). The present invention provides useful supramolecular complexes wherein an agent of interest is specifically bound to a host via non-covalent interactions, and wherein the host is conjugated to a tag. The present invention also provides methods and compounds useful in preparing supramolecular complexes, and methods of treating diseases using the supramolecular complexes.