When it comes to steroids, undoubtedly the side effects that scare people the most are those related to estrogen and its side effects. This is very common when you consider the fact that as a man, the primary reason you have masculine features is due to higher levels of testosterone in comparison to estrogen. For women, the inverse is true. This is very important to understand because whenever you dose with an exogenous compound, you’re going to throw your hormone levels out of whack. This means that whenever you do engage in using one of these compounds, you have to understand that whenever you introduce higher levels of androgenic (testosterone producing compounds) compounds, these are going to result in feedback levels of estrogen in response. This is very important to keep in mind because otherwise, you will be unable to stave off the bad effects that you would otherwise experience from the compound.
In androgen-responsive target tissues such as the skin, scalp, and prostate, the high relative androgenicity of testosterone is dependant on its reduction to dihydrotestosterone (DHT). The 5-alpha reductase enzyme is responsible for this metabolism of testosterone. The concurrent use of a 5-alpha reductase inhibitor such as finasteride or dutasteride will interfere with site-specific potentiation of testosterone action, lowering the tendency of testosterone drugs to produce androgenic side effects. It is important to remember that both anabolic and androgenic effects are mediated via the cytosolic androgen receptor. Complete separation of testosterone’s anabolic and androgenic properties is not possible, even with total 5-alpha reductase inhibition.
Because the ultimate goal of a steroid cycle is to increase strength and muscle size, the associated spike in estrogen which accompanies steroids such as Testosterone is considered undesirable. In order to disassociate the two effects, two classes of drug are used. Medications such as Nolvadex or Clomid target the estrogen receptors. They make it more difficult for the estrogen to exert it’s influence within the body thus allowing the testosterone to act more freely. The second class is aromatase inhibitors such as Femara. They target the aromatase enzyme itself in order to prevent the production of estrogen in the first place. Sometimes, it’s not always clear which option you should go with or even what the differences are between the two. Lets clear that up a little.