A formulation composed of a sugar such as glucose and a surfactant such as myristoyl lysophosphocholine (LMPC) has been designed to stabilize both hydrophilic and hydrophobic portions of the glucagon molecule, under prolonged physiological conditions, in a formulation that is sufficiently similar to the pH and osmolarity of plasma so as not to induce or to minimize site irritation. The combination of a simple sugar and an surfactant stabilizes the glucagon molecule in an aqueous solution for seven days at 37° C.