<unk>  (Lentaron) is a type I, steroidal aromatase inhibitor.  It is used in the treatment of estrogen-receptor positive breast cancer in post-menopausal women.  It is available as an intramuscular depot injection.<unk>  is often used to suppress estrogen production from anabolic steroids or prohormones.  It also acts as a prohormone to 4-hydroxytestosterone, an active steroid which displays weak androgenic activity in addition to acting as a mild aromatase inhibitor.<unk>  has poor oral bioavailability and as such is no longer popular as many orally active aromatase inhibitors have been identified.
It is selective.
Formestane
Gestodene
Fosfestrol
Megestrol
Proligeston
Exemestane
Leuprolide
Gestrinone