Continue reading Stack3d


With the demise of ATD, 6-bromo, and 6-oxo, the supplement industry needed a new powerful anti-estrogen and arimistane (androsta-3,5-diene-7,17-dione) has taken the reigns as the most powerful and bestselling anti-estrogen ever since.

What it does

Arimistane is sold as an anti-estrogen and aromatase inhibitor. When estrogen significantly reduces, it results in higher testosterone levels due to a process known as the “negative feedback loop”. Since males do not have ovaries, the only source of estrogen in the body is via conversion of testosterone to estrogen via the aromatase enzyme. If this enzyme is inactivated, the body is unable to perform the conversion, resulting in significantly lowered estrogen levels.

As estrogen continues to plummet, the body attempts to correct the hormone imbalance by increasing testosterone levels in the hopes some of it will be acted upon by aromatase, yet as long as an aromatase inhibitor is still being taken, this is unable to occur. As a result, users will experience much higher than normal testosterone levels. Arimistane users commonly report increased lean muscle growth and muscle hardness, as well as the ingredient being an effective post cycle therapy option after OTC prohormone cycles.

How it works

Arimistane works via binding to the aromatase enzyme[1] and does so with an extremely strong binding rate of .22 micromolar (stronger than the highly coveted ATD and 6-oxo).

Arimistane acts as a “suicidal inhibitor” of the aromatase enzyme, meaning once it binds, it is incapable of releasing until the body eliminates the enzyme from the body. As such, this compound will directly cause decreased estrogen levels while simultaneously increasing testosterone levels making a great option for use on its own, or after prohormone cycles as a PCT.


Most suggest a maximum dose of ~75mg/day of arimistane, usually split into three 25mg doses throughout the day. While 75mg is the most commonly suggested dosing, this more than likely is a result of the high cost of this raw material, and doses up to 150mg/day may increase benefits.