Stabilized glucagon solutions, methods of storing and using the stabilized glucagon solutions, and drug delivery devices containing the stabilized glucagon solutions. In some embodiments, the glucagon solutions may be alkaline, such as with a pH of at least about 9. The glucagon solutions may be resistant to aggregation of glucagon when the solutions are stored for a prolonged period, such as at least about three days, at room temperature and/or physiological temperature.
