Aromatase inhibitors (AI), which prevent testosterone from being converted to estrogen, are used in bodybuilding products to supposedly maintain testosterone levels and thus help increase muscle mass. Arimistane (androsta-3,5-diene-7,17-dione), ATD (3,17-keto-etiochol-triene), 4-androstene-3,6,17 trione (6-oxo), and Androsta-1,4,6-triene-3,17-dione (androstatrienedione) are examples of AIs. At this time, AIs are considered drugs (used primarily in the treatment of breast and ovarian cancer). As a result, dietary supplement products should not contain AIs as ingredients. Aromatase inhibitors should not show up on a routine military drug test, but they are included in the DoD Prohibited Dietary Supplement Ingredients list and are prohibited for use in sport by WADA (the World Anti-Doping Agency). In addition, there are concerns about serious side effects associated with their use.


Updated 25 April 2022