What does aldara cream do when it is applied on healthy skin? melanoma? why aldara cream is preferred than other treatments though it takes several months to see results?

Not for Melanoma: Aldara (imiquimod) is an immune response modifier. Aldara is used to treat actinic keratosis (a condition caused by too much sun exposure) on the face and scalp. Aldara (for the skin) is also used to treat a minor form of skin cancer (superficial basal cell carcinoma), and warts on the external genitals. It is not used for Melanoma.