Arimidex (Anastrozole) There are several Aromatase Inhibitors available, Femara (Letrozole), Aromasin (Exemestane) and Arimidex (Anastrozole) being the most common. All three are very similar and while all three carry slight differences that make them unique many agree Arimidex may be the most valuable of all. For the anabolic steroid user, Arimidex doses can vary with 0.5-1mg every other day being the most common.