Compounds which function as melanocortin receptor ligands and having utility in the treatment of melanocortin receptor-based disorders, and may be used to treat disorders or illnesses including eiating disorders, cachexia, obesity, diabetes, metabolic disorders, inflammation, pain, skin disorders; skin and hair coloration, male and female sexual dysfuntion, erectile dysfunction, dry eye acne and/or Cushing's disease. The compounds have the following structure (I): including stereoisomers, prodrugs, and pharmaceutically acceptable salts thereof, wherein A, m, n R1, R2, R3a, R3b, R4, R5, R6, W1, W2, W3, W4, Y1, Y2, Y3 and Y4 area defined herin. Pharmaceutical compositions containing a compound of structure (I), as well as methods relating to the use thereof, are also disclosed.