1,4,6- androstatrien-3,17-dione

1,4,6- androstatrien-3,17-dione, also known as ATD is an aromatase inhibitor used to control estrogen synthesis.

1,4,6- androstatrien-3,17-dione is used in over-the-counter bodybuilding supplements such as Rebound XT, Novedex XT and Inhibit-E, and while not banned, may cause positive urinanalysis results leading to disqualification from competitive sports due it's similar properties to banned substances.