Abstract: Compositions and methods for enhancing the stability of rapid acting injectable insulin formulations have been developed for subcutaneous injection. The formulations contain insulin in combination with a zinc chelator such as ethylenediaminetetraacetic acid (“EDTA”), a dissolution/stabilization agent such as citric acid, a magnesium salt, a zinc compound and, optionally, additional excipients. New presentations include rapid acting concentrated insulin formulations and a way to enhance the absorption of commercially available rapid acting analog formulations while maintaining insulin stability.