what is an aromatase inhibitor
Aromatase inhibitor: A drug that inhibits the enzyme aromatase and by that means lowers the level of the estrogen estradiol. Aromatase inhibitors represent a class of antiestrogens. Aromatase catalyzes the conversion of testosterone (an androgen) to estradiol (an estrogen) in many tissues including the adrenal glands, ovaries, placenta, testicles, adipose (fat) tissue, and brain. Estrogen is produced directly by the ovaries and is also made by the body using aromatase. Aromatase inhibitors cannot do anything about estrogen produced by the ovaries, but they do interfere with the body's use of aromatase. The growth of many breast cancers is promoted by estrogens.