Arimidex and E-2

[Genetic Freak]

A while ago I posted comments regarding the effectiveness of Arimidex on E-2...

In it I suggested: Arimidex's mechanism of action was to stop the conversion of androstenedione to estrone and didn't have as much of an effect on the conversion of testosterone to estradiol.

The key here is that the production of estradiol is different in females than what it is in guys with large amounts of testosterone in their body. In women the majority of estradiol is synthesized via androstenedione which is converted to estrone and then to estradiol which is why arimidex is so effective in lowering estradiol in women. Women do not convert much androstenedione to testosterone in their ovaries as there is no expression of 17-Beta-HSD-3 the enzyme which is hugely important for this step in men.

In men however large amounts of exogenous testosterone is converted directly into estradiol which is why I think arimidex may not be as effective in lowering estradiol in men. This was my thinking in my earlier message...???


I have recently been made aware of 3 studies backing arimidex suppressing E2..

http://www.ncbi.nlm.nih.gov/pubmed/7626450

http://www.ncbi.nlm.nih.gov/pubmed/10902781

http://www.ncbi.nlm.nih.gov/pubmed/8595172

 

[BlueCrest]

Anastrozole's mode of action is to block the aromatase enzyme. There's only one type of aromatase and this one enzyme is required for both estrogen-producing reactions:
- androstenedione -> estrone
- testosterone -> estradiol

I'd like to hear the source of the claim that adex doesn't prevent the conversion of testosterone to E2 because I think it's nonsense.

 

[Genetic Freak]

Anastrozole's mode of action is to block the aromatase enzyme. There's only one type of aromatase and this one enzyme is required for both estrogen-producing reactions:
- androstenedione -> estrone
- testosterone -> estradiol

I'd like to hear the source of the claim that adex doesn't prevent the conversion of testosterone to E2 because I think it's nonsense.

I think the suggestion was that Arimidex's action on E-2 was limited or not as effective.... Rather than being totally preventative.....

The reason for my post was to correct an earlier post, that I now believe to be incorrect....

My earlier arguement was placed on some overseas boards a few years ago & there was some supporting evidence for using Aromasin in favour of Arimidex because of the nature of how Aromasin works as a suicide inhibitor & effectively kills the aromatase enzyme vs how arimidex just binds to it & can be eventually released. I believe it had something to do with promoting the use of aromasin which is a more expensive drug. I agree though that most studies done are in relation to how E1,E2,E3 work in females & do not take into account males using high doses of exogenous testosterone. However, it does not negate the fact that Adex is still effective at reducing serum E2 in males as is Letrozole & Aromasin. The key in using them is to not overdose unless yr pre contest where its "Better to look good, than feel good"