Aromasin (Exemestane) : This drug is classified as a Type I Suicide AI. It binds to the aromatase enzyme and kills it. It is effective at lowering estrogen up to 85%. Once again, you have to watch out for your cholesterol levels. Used mainly for cutting when low estrogen levels are desired. Aromasin is shown to help bone density. Clinical doses are about 25mg a day, but it has been shown that as little as 2.5mg a day can be as effective.
Arimidex (Anastrozole) : This is a widely used type II AI. It competes with estrogen aromatase enzyme. This effectively lowers estrogen up to 80% in the blood. Approved for use in 1995 to fight breast cancer. At doses up to 1mg a day, it has been shown to be very effective at controlling estrogen while on cycle or in PCT. It is usefull for curbing the effects that come with aromatizing AAS's while in cycle, and can be used in PCT. Nolvadex is shown to decrease the effectiveness of Arimidex PCT. In this case a suicide inhibitor may be more well suited, like in PCT. It is also called L-dex, in its liquid form. It is also called L-dex, in its liquid form.
So yes you can substitute it, but it might not be
quite as effective.