Arimidex (anastrozole) was the first selective aromatase inhibitor used in bodybuilding, and is still the most popular estrogen control drug. It’s commonly available in both tablet and liquid form for oral use. Dosing is typically 0.25, 0.5, or 1.0 mg at a time, at a frequency of once per day or per two days.
Estradiol, the most potent form of estrogen, is produced in the body by aromatization of testosterone. This occurs via the aromatase enzyme. Because certain levels of estradiol are needed for men, some conversion of testosterone to estradiol is required. However, in two circumstances effective aromatase inhibition can give important benefits.
First, when an anabolic steroid cycle causes very aromatizable steroid levels and there is no control of the aromatase enzyme, conversion to estradiol becomes excessive. The resulting high estradiol can cause gynecomastia, water retention, depression, and/or loss of libido. It may also make it difficult to maintain a lean condition.
And second, some men have excessive estradiol levels even when not on an anabolic steroid cycle. This will act to decrease their natural testosterone production, and can also cause the above adverse side effects.
Arimidex is highly suitable for solving either problem. With correctly chosen dosing, free estradiol level can be brought fairly accurately to a desired range. When not using anabolic steroids, for most men I recommend about 20-29 pg/mL for best effect on mood, performance, libido, and long term health and to provide excellent benefit to natural testosterone production. During a steroid cycle, levels can be allowed to rise a little higher, because high androgen levels act towards countering adverse actions of estradiol. Sometimes levels are deliberately made higher, as being a little “wet” can improve lifting performance. Still, I recommend that even during a strong anabolic cycle, estradiol level be kept to no more than about 40 pg/mL.This will usually require an aromatase inhibitor such as Arimidex, if dosing of aromatizable steroidsis high.
The most highly aromatizing steroids are testosterone, methyltestosterone, and Dianabol, but Deca (nandrolone) and Equipoise (boldenone) also aromatize.
Most medical studies of effect of Arimidex on men have used it at 1 mg/day, with this dosage appearing about optimal judging from effect on estradiol level. However, real world use for either steroid cycles or optimization of hormone levels is generally at a lower dosage, from 0.25 mg every other day to about 0.5 mg/day. I generally recommend 0.5 mg every other day as a starting point for a steroid cycle, and half that for hormone optimization if a high estrogen problem exists.
