Understand a Type-II and Type-I aromatase inhibitor

Zewi

Well-known member

First you need to Understand a Type-II and Type-I  aromatase inhibitor.

Type I inhibitors (like Aromasin) are actually steroidal compounds, while Type-II inhibitors (like Letro and A-dex) are non-steroidal drugs. Of course, there are some similarities between the two types of AIs…both type I & type II AIs mimic normal substrates (essentially androgens), allowing them to compete with the substrate for access to the binding site on the aromatase enzyme. After this binding, the next step is where things differ greatly for the two different types of AI’s. In the case of a type-I AI, the noncompetitive inhibitor will bind, and the enzyme initiates a sequence of hydroxylation; this hydroxylation produces an unbreakable covalent bond between the inhibitor and the enzyme protein. Now, enzyme activity is permanently blocked; even if all unattached inhibitor is removed. Aromatase enzyme activity can only be restored by new enzyme synthesis. Now, on the other hand, competitive inhibitors, called type II AI’s, reversibly bind to the active enzyme site, and one of two things can happen: 1.) either no enzyme activity is triggered or 2.) the enzyme is somehow triggered without effect. The type II inhibitor can now actually disassociate from the binding site, eventually allowing renewed competition between the inhibitor and the substrate for binding to the site. This means that the effectiveness of competitive aromatase inhibitors depends on the relative concentrations and affinities of both the inhibitor and the substrate, while this is not so for noncompetitive inhibitors. Aromasin is a type-I inhibitor, meaning that once it has done its job, and deactivated the aromatase enzyme, we don’t need it anymore. Letrozole and Arimidex actually need to remain present to continue their effects.http://thinksteroids.com/steroid-profiles/aromasin/

Arimdex binds to Estor but it will let go, thats why it’s a s a type-II aromatase inhibitor(just like letro but letro is 40% more effective in getting rid of estro)—Also a reminder if you are using Adex do not use Nolvadex as Nolvadex will reduce the blood plasma levels of Arimidex, it also does that to Letro also.

Where Aromasin is a Type-I aromastase inhibitor it binds to estor and does not let go. So if your prone to Gyno use Aromasin. Aromasin is about 65% efficient at suppressing estrogen  it’s certainly a very powerful agent, There is also a decent amount of preclinical data suggesting that Aromasin has a beneficial effect on bone mineral metabolism that is not seen with non-steroidal agents, and it may also have beneficial effects on lipid metabolism that are not found in the non-steroidal Letro and A-dex

Also what makes Aromasin so great is Aromasin, also helps out your free to bound testosterone ratio by lowering levels of Sex Hormone Binding Globulin (SHBG), by about 20% SHBG is that nasty enzyme that binds to testosterone and renders it useless for building muscle. Because of this it makes Aromasin a great addition to your PCT.

IMO—Aromasin is the best AI to use because it’s a type 1 and its extra benefits, nothing wrong with Adex it has its place. And I do use it in short 8 week cycles for cutting as Adex will Dry you out.

Letro is hard and should only be used if you have signs of gyno not as your AI. 

 

Semper Fi

New member

Managing Estro has not been a concern yet but I am sure will be in the future as my cycles progress.  From what I have gathered (Hard to tell the actual science vs the bro-science) Proviron may be the better choice for me.  It seems to help with free test and sex drive more effectively (Important for me).  I also gather that Proviron is "less" effective as an AI but if I am not prone to High Estro buildup then could it be better suited for me?

Currently plan to run Proviron @ 25mg ED next cycle and have Adex on hand just in case.

Also, since I have yet had to use/need an AI, do you have/know of a process in which people can evaluate when/if needed and how to add/subtract the dosages?  I want to learn how to “Manage my estro to find the SWEET spot” - Wow – maybe that should be a thread topic.

Feedback appreciated and thanks for the topic.

 

Semper Fi

 

Zewi

Well-known member

Proviron is an important compound to any cycle. Main reason is it allows more floating test, but it also helps prevent Testosterone from converting to Estrogen which is a very good thing. It also has a small effect at blocking estrogen also. Like a low dose of Mast. and it lowers youre Sex Hormone Binding Globulin (SHBG).

So when should you use Proviron.

1. Really any cycle Proviron has a half life of 12 hrs so taking 25mg every 12hrs is perfect. You will get more benefits on you cycle with more test floating around because proviron helps prevents test from converting to estro.  Which also helps when your using an AI or if you are keen to gyno.

2. Also take Proviron when on a Deca cycle. Deca is a great compound however, it does two things one is Deca Dick and the other Deca helps test convert to Estor. But using Proviron during a Deca cycle will prevent Deca Dick and it will counter act Deca trying to convert Test into estor. 

3. During a PCT with its low AI properties and the Ability to keep that libido high and your Dick hard as rock helps.

4. Proviron Used as a bridge, Proviron does not shut you down it helps increase your LH which we all know LH is what your body needs to make your natural test. Because proviron does not shut you down you can take it between cycles, and it will also help increase your natural floating test in your body because again it helps prevent test from converting to estro.

 

built_tough

New member

i should also mention that not everyone will be able to use Adex , due to being "non responsive", such as myself as i have found out.  I was using adex and nips started getting somewhat tender, so i used nolva, which was stupid on my behalf, but then i transfered over to strictly aromasin and guess what.  the sore nips went away.  just saying that there is a percentage of people where adex is utterly useless to them.  so , my AI will forever be Aromasin. 

 

kiddbiggdogg

New member

man thank you for clearing that up... in doing my research some of the material i read had it screwed up and i wasnt sure. GREAT POST

 
Top