Anastrozole is a very powerful anti-estrogen that officially belongs to a class of medicines called flavor inhibitors. It was introduced on the market in 1995 under the name Arimidex. Gradually became one of the most popular anti-estrogens, along with Nolvadex (tamoxifen). It is used in medicine for the treatment of breast cancer, being much more effective in this regard than tamoxifen.
Bodybuilders and athletes using anabolic and androgenic steroids greatly use Arimidex to prevent side effects of estrogenic nature. In the past, Proviron used for similar effects, but is much weaker and can have androgenic side effects.
Anastrozole acts by blocking the enzyme responsible for the conversion of testosterone into estrogen, an enzyme called aromatase. When we say that a steroid is aromatized, it is altered by this enzyme, which leads to the accumulation of estrogens in the body with side effects such as water retention, fattening and worst gynecomastia. Anastrozole is very effective in reducing estrogen, and can go up to a reduction of 80%. This reduction is beneficial to those who use anabolic steroids and especially to breast cancer patients.
Arimidex can also stimulate the secretion of luteinizing hormone and follicle stimulating hormone, two hormones that signal the release of testosterone from the testicles. That's why some doctors use Arimidex in men with low testosterone, but it's generally not a good solution. In such cases, it is best associated with testosterone injectable in therapeutic doses.
Medical is useful for breast cancer patients because many such tumors feed on estrogen. It's a simple simplification, but practically Arimidex infects tumors until they die. Long time Nolvadex was used for this. But it acts in a different way: it attaches itself to estrogen receptors preventing estrogen from binding them. Estrogen is still present in the blood but can not exert its action. Arimidex inhibits estrogen production and there is less hormone in circulation. Currently, Arimidex is the most commonly used medicine for treating breast cancer, especially in postmenopausal women. After the cancer has disappeared, tamoxifen is taken to prevent a relapse.