I'm using aromasin instead. I actually need to sit down and really learn the differences between the various AIs.
You have two options steroidal (e.g., formestane and exemestane [AROMASIN]) and non-steroidal agents (e.g., anastrozole [ARIMIDEX], letrozole [FEMARA], and vorozole)...
Steroidal (type 1) agents are substrate analogs that act as suicide inhibitors to irreversibly inactivate aromatase, while the non-steroidal (type 2) agents interact reversibly with the
heme groups of CYPs, primarily CYP19A1..
Steroidal (type 1) bind irreversibly for the life of the enzyme CYP19A1 responsible for synthesizing testosterone to estrogen, Non-steroidal (type 2) only bind until the medication had been metabolized and excreted from the body.
Anastrozole shows maximal blood concentrations at 1 hour presenting slow elimination kinetics, with a half life of about 46hrs, Letrozole works predominantly on adipose tissue (also in brain), presents with a 2 day half life, particularly useful for gyno presentation if caught early.. (smoking could effect kinetics of letrozole)..