Exemestane Powder Aromasin API Aromatase Inhibitor For Sale What is Aromasin (Exemestan) ? Exemestane is a steroidal Aromatase Inhibitor (KI) that is most commonly known as Aromasin. Eigentlich, the Aromasin brand name is the only pharmaceutical grade brand of the Exemestane AI due to the tight patent Upjohn has maintained on the product. While tightly controlled by the pharmaceutical …