This article needs attention from an expert in Pharmacology.
1,4,6-androstatrien-3,17-dione (ATD) is a potent irreversible aromatase inhibitor that inhibits estrogen biosynthesis by permanently binding and inactivating aromatase in adipose and peripheral tissue. 
A related agent is exemestane (Aromasin).
- Covey DF, Hood WF. (1981). "Enzyme-generated intermediates derived from 4-androstene-3,6,17-trione and 1,4,6-androstatriene-3,17-dione cause a time-dependent decrease in human placental aromatase activity". Endocrinology 108 (4): 1597-9. PMID 7472286.