ACTH analog compounds of the present invention include compounds comprising an ACTH peptide sequence with one or more structural modifications that can have one or more of the following preferred ACTH analog biological functions: (1) reduction of corticosteroid secretion by adrenal membrane in the presence of the ACTH analog compared to unmodified ACTH, (2) reduction of corticosteroid secretion by adrenal membrane in the presence of endogenous ACTH and (3) increased MC-2R binding affinity with reduced activation of the MC-2R receptor compared to unmodified ACTH binding to the MC-2R melanocortin. The ACTH analog compounds of the present invention are therefore useful for treatment or prevention of diseases and disorders related to ACTH, ACTH receptors or corticosteroid secretion, such as premature labor and Cushing's Disease.