A melanocortin receptor-specific compound of the general formula of structure I: where X, R1, R2a, R2b, R3, R4a, R4b, R5a and R5b are as defined in the specification, which compound binds with high affinity to one or more melanocortin receptors and is optionally an agonist, an antagonist, an inverse agonist or an antagonist of an inverse agonist, and may be employed for treatment of one or melanocortin receptor-associated conditions or disorders, and methods for the use of the compounds of the invention.