The present application provides methods of administering an IL-22 dimer to an individual, such as a human individual, comprising intravenously administering to the individual an effective amount of an IL-22 dimer, wherein the amount of the IL-22 dimer is about 2 μg/kg to about 200 μg/kg (such as about 10 μg/kg to about 45 μg/kg), as well as methods of treating diseases by following such administration methods. Also provided are kits, unit dosages, and articles of manufacture for use in any one of the methods described herein.