Anastrozole is an extremely popular Aromatase Inhibitor (AI) that first appeared on the market in 1995 under the trade name Arimidex given to it by Zeneca Pharmaceuticals. This is largely the only trade name of any consequence. Anastrozole is also commonly manufactured by research chemical labs (RCLís), but most refer to all brands as ďAdexĒ the shorthand for Arimidex. There are no other well-known names associated with this AI.

Arimidex was created in an effort to combat breast cancer, specifically breast cancer in post-menopausal women. This compound has a strong anti-estrogenic effect, and estrogen is the enemy of a breast cancer patient. For decades, Selective Estrogen Receptor Modulators (SERMís) were used for this purpose, such as Tamoxifen Citrate (Nolvadex) but Arimidex has proven to be far more effective. Once this power was realized, many bodybuilders began using Arimidex for its strong anti-estrogenic effects in order to combat possible related side effects of steroid use.

Basic Function of Arimidex:

Arimidex is a fairly easy compound to understand. By its natural mode of action, Arimidex inhibits the aromatase enzyme, which is responsible for the production of estrogen. SERMís do not have this ability. SERMís merely prevent the estrogen from attaching or working at the receptor site. Arimidex also takes it a step further by reducing total estrogen levels. In fact, this AI can reduce total levels by as much as 80%. Once again, SERMís do not carry this related trait.


The basic function of Arimidex is easy to see when it pertains to breast cancer. Breast cancer thrives on estrogen, its production is halted and total levels reduced thereby promoting therapy. For the performance enhancing athlete, Arimidex works the same way, but in this case, weíre trying to prevent specific steroid related side effects. Any anabolic steroid that aromatizes can lead to gynecomastia (male breast enlargement) and excess water retention. Not all steroids aromatize, but testosterone and most testosterone derived compounds will. An AI like Arimidex is the primary protection against related effects. Unfortunately, it can also impact cholesterol levels and should not be used unless absolutely necessary. Cholesterol can be controlled, however, if you can control the side effects with a SERM this is the best way to go, but it wonít be enough for a lot of men.

Side Effects of Arimidex:

The side effects of Arimidex, while some can be harsh, will overall fall into the rare category. This is a rather side effect friendly medication. Most who use it will not experience any side effects of notable worth, but we can make a possible exception when it comes to anabolic steroid users. The conjoined use of testosterone and Arimidex appears to have a strong negative impact on HDL cholesterol levels. Total levels will decrease substantially. This can be corrected with diet, but it will take some concentrated effort on your part. Other possible side effects of Arimidex you should be aware of include:

  • Decreased Mineral Density
  • Depression
  • Fatigue
  • Headaches
  • High Blood Pressure
  • Hot Flashes
  • Joint Pain/Discomfort
  • Nausea
  • Swollen Extremities
  • Vomiting
  • Weakness

These side effects will be rare in most who use the compound safely. However, genetic response will dictate more than anything else. This is a principle that holds true with all medications, and even in relation to many of the foods we eat.

Arimidex Ė Total Use:

In breast cancer patients, Arimidex is always given at a dose of 1mg per day every day until the cancer is no longer growing. From there, the dose may be reduced, but itís commonly continued for a long period of time until the cancer is gone and even afterwards in order to keep it in remission. Each instance is viewed on a case-by-case basis in order to determine the need.

For performance enhancement athletes, Arimidex is normally used on cycle pertaining to when anabolic steroids are used. This is the only time we can recommend its use. Some will use it for Post Cycle Therapy (PCT) purposes as it carries strong natural testosterone promoting effects; however, it does not promote overall normalization. For side effect protection while on a cycle of anabolic steroids, the most common dose is 1mg every other day. This is enough to protect most men, and many men will be fine with half that amount. There are those who will need stronger protection and a daily dose would be the next step. However, daily is normally not necessary to combat side effects.