Anastrozole (also known as armidex) is a non-steroidal aromatase inhibiting drug (acronym AI) developed in 1995 by Zeneca Pharmaceucitals for treatment of breast cancer after surgery and for metastasis in women. Anastrozole is used to inhibit the synthesis of estrogen.

Anastrozole use in bodybuilding. When male athletes use anabolic steroids, some of them convert by the aromatase enzyme into the female hormone estradiol (aromatization). The most aromatizing steroids are testosterone esters and methandienone. If estradiol is not inhibited by taking aromatase inhibitors (AI), unpleasant side effects may occur. The most common of them is gynecomastia, i.e. the build-up of female breast tissue in men under impact of female hormone estradiol. Estradiol also causes water retention and increase in the amount of subcutaneous fat. As a result, you can get a rise in blood pressure, heart strain and depression. High levels of estradiol may adversely affect libido.

On the other hand, anastrozole in high quantities or stronger aromatase inhibitors can suppress estradiol too much. As a result, we can expect as well erectile dysfunction, loss of energy, depression.

The main advantage of anastrozole as compared to antiestrogens (SERMs) such as tamoxifen or clomiphene consist in the fact that anastrozole blocks production of the aromatase enzyme, hence, prevents estradiol generation at the earliest stages, while antiestrogens only prevent contact of estradiol with the corresponding receptors by binding to them instead of estradiol, but don’t reduce its production in the body .Therefore, estradiol may still circulate in bloodstream in large amounts when you take antiestrogens.

Anastrozole has no harsh side effects. Actually, affecting estradiol, it can suppress the level of the good cholesterol (HDL). However, when compared to AI like letrozole, anastrozole is preferable.  Letrozole has quite a few side effects, the most common of which is erectile dysfunction. Although estradiol is known as a female hormone, men still need it. Estradiol maintains hormonal balance, participates in a great number of physiological processes and helps to gain muscle mass and strength. Such potent AI as letrozole kills almost all estradiol, disrupting the hormonal balance and causing a number of side effects, such as erectile dysfunction, joint pain, bones fragility, unwellness, etc. Anastrozole acts more smoothly and does not kill all estradiol immediately, allowing you to more finely adjust the hormonal balance.

The initial recommended dose of anastrozole 0.5 mg per day or every other day. Remember, the anastrozole dosage depends on the dose of aromatizing steroids on cycle.

• Chemical name2,2′-[5-(1H-1,2,4-triazol-1-ylmethyl)-1,3-phenylene]bis(2-methylpropanenitrile)
• FormulaC17H19N5
• Anabolic activity indexnot a steroid
• Androgenic activity indexnot a steroid