Ionic liquids have considerable potential to advance formulation science for protein-based pharmaceutical preparations and cellular therapies. Extended shelf life has been reported for a number of model proteins in rationally designed ionic liquid formulations (1-4). Biocompatibility is also an important aspect of rational design of pharmaceutical additives that are co-delivered into the body with a therapeutic. Using mouse macrophage cells as models for toxicity testing, biocompatibility has been established for a number of these bio-inspired ionic liquids, including salts based on the choline cation. Other important facets of clinical translation have also been elucidated. Here, we overview progress towards clinical application of ionic liquids and identify some of the challenges that remain.