Drugs that inhibit the enzymeA substance produced by a living organism which causes a specific biochemical reaction. aromatase, which regulates estrogenA female sex hormone that is primarily produced by the ovaries. Its primary function is to regulate the menstrual cycle and assist in the production of secondary sex characteristics such as breasts. It may even play a role in the production of cancer cells in the breast tissue. production in the adrenal glandsAn organ in the human or animal body which releases particular chemical substances for use in the body or for discharge into the surroundings.. An example is anastrozole (Arimidex).