I have been reading as much as I can on the use of Aromasin in PCT. How it works and why? First there are plenty of write ups on standard PCT on this site. So I'll just skim over Clomid and Nolva quickly.
Clomid and Nolvadex are both anti-estrogens belonging to the same group of triphenylethylene compounds. They are structurally in the same family and specifically classified as selective estrogen receptor modulators (SERMs) they act in two ways. One is by changing up the binding capacity of the receptor, then in others they can actually act as estrogen, activating the receptor. In men, both of these drugs act as anti-estrogens in their capacity to oppose the negative feedback of estrogens on the hypothalamus and stimulate the release of GnRH (Gonadotropin Releasing Hormone). LH output by the pituitary will be increased as a result, which in turn can increase the level of testosterone produced at the testes.


That's a quick summary of why we use both Clomid and Nolvadex on a PCT. The dose has been wildly played with over the years and guys have figured out that a dose of 100/100/50/50 of clomid and 40/40/20/20 of Nolvadex has proven to work very well.
HCG is another debatable form of PCT. Over the years I have found that HCG is best served with "ON" cycle use. It prevents an extended period of HPTA shutdown therefore making a reboot of that axis much more feasible and without heavy blast doses of hcg which in my opinion does as much detriment as it does benefit th user. Heavy doses will trigger the production of more estrogen counteracting the entire purpose of PCT. Which is to re-regulate the levels of test vs estrogen to the appropriate levels of homeostasis. It was this topic that led me to the Idea of using Aromasin as part of PCT. What I found researching this topic was quite interesting.


Well, Aromatase Inhibitors come in 2 types. Type 1 and Type 2. First Type 1 AI's bind by a process called hydroxylation; this hydroxylation process produces an unbreakable covalent bond between the inhibitor and the enzyme protein. Now the enzyme is permanently blocked even after all of the inhibitor is removed and can only be resumed by new enzyme synthesis. Type 2 Inhibitors on the other hand function all the same in their ability to reduce the binding process of the enzyme and the receptor. Except once the drug is discontinued or the concentration of the drug is sparse enough it is possible for the enzyme to seperate itself from the Inhibitor and eventually will allow renewed competion between the Inhibitor and the Enzyme for the receptor site. Aromasin is a type 1 AI and once it does what it's purpose is we don't need to continue use. Letro and Adex are Type 2 Ai's and the success of those drugs are continigent on the Doses and protocol of which we use them. Once you stop them you expose yourself to an Estrogen rebound. Now having said all of that there are also many other reason to why Aromasin use is beneficial to a Bodybuilder. One is Arimidex/Anastrozole Decreases IGF-1 18% while Aromasin/Exemestane Increases IGF-1 28%. Another is Aromasin is also known to decrease estrogen between 90-95% while boosting Endogenous Testosterone by about 60%, and also help out your free to bound testosterone ratio by lowering levels of Sex Hormone Binding Globulin (SHBG), by about 20% (12)�SHBG is that nasty enzyme that binds to testosterone and renders it useless for building muscle.
So let put all of this together. We need to ask ourselves what exactly are our goals for a successful PCT? 1) Reboot the HPT Axis; that's where the Clomid/Nolva/Hcg and Aromasin come in to play 2) Control the conversion of Aromatase as the Levels of exogenous Test decline; aromasin is scientifically proven to permanently deactivte the Aromatase Enzyme for the life of the Enzyme. In essence there is no possible Estrogen rebound as a byproduct of the Medications discontinued use.


I recommend running Aromasin @ 12.5/12.5/.6.25/6.25 alongside the standard Clomid Nolvadex Pct for optimum recovery and zero estrogen rebound.
So all of these facts are just the tip of the iceberg. There are more interesting facts and write ups all over the Web. Some are very scientific but I get bored with all of that mumbo jumbo talk. I need it said to me in leymans terms. So I wanted to simplify what I have read. I hope this helps somebody who has questions about this topic.