1,4,6-Androstatriene-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. It is used to control estrogen synthesis.
ATD is present in some over-the-counter bodybuilding supplements as well as Topical ATD solutions that work transdermally. While not banned, ATD may cause positive urinalysis results leading to disqualification from competitive sports. ATD has many names in sports supplements including: 1,4,6 etiollochan-dione, 3, 17-keto-etiochol-triene, androst-1,4,6-triene-3,17-dione and many others. These all refer to CAS# 633-35-2.
ATD may cause a positive test for the anabolic steroid boldenone, of which it is a metabolite and is also prohibited in amateur and professional sports which forbids aromatase inhibitors.
A related agent is exemestane (Aromasin).