Zoladex

Zoladex blocks the ability of the ovaries to make estrogen. ..effectively causing a chemical menopause. An aramatose inhibitor works on blocking the bodies ability to use the estrogen we produce in body fat, which is what women who have gone through menopause take.

This link may explain it for you. Hope it helps.

http://www.cancerresearchuk.org/about-cancer/type/breast-cancer/treatment/hormone/types-of-breast-cancer-hormone-therapy

http://www.cancerresearchuk.org/about-cancer/type/breast-cancer/secondary/treatment/hormone-therapy-for-secondary-breast-cancer