What is an aromatase inhibitor and how does it work?
Despite the drop in oestrogen levels at the menopause, small amounts of oestrogen continue to be produced in other parts of the body, by changing other hormones (androgens) into oestrogens.
The body does this using an enzyme called aromatase. This enzyme can be blocked using aromatase inhibitor (AI) medication. Blocking this enzyme therefore blocks the production of oestrogens.
The most widely used types of AI medication are letrozole, anastrozole and exemestane. Hundreds of thousands of women affected by breast cancer take this treatment every day.