# Aromatase inhibitors are anti-anabolic in rodent study



## Arnold (Jan 24, 2011)

*Aromatase inhibitors are anti-anabolic in rodent study*
_by Anthony Roberts_

Within the steroid using community, it has become a well established fact that estrogen helps promote weight and strength gain. Steroids that don???t convert to estrogen (non-aromatizing compounds) typically do not provide the same degree of results as those which have some conversion to estrogen. We see this further proven by anti-estrogenic compounds, such as aromatase inhibitors, which, when added into a cycle, typically reduce gains. Estrogen, therefore, is anabolic, and compounds that reduce it, can properly be termed as anti-anabolic.

Remember, when something is anti-anabolic, it impairs the building of new tissue, as opposed to catabolic, which actually breaks tissue down.

Now, a recently published study has provided evidence of impaired body weight gain (an anti-anabolic effect), in male rodents given exemestane, a suicidal aromatase inhibitor:

    Horm Res Paediatr. 2010;73(5):376-85. Epub 2010 Apr 14.
    Impaired body weight and tail length gain and altered bone quality after treatment with the aromatase inhibitor exemestane in male rats.

    van Gool SA, Wit JM, De Schutter T, De Clerck N, Postnov AA, Kremer Hovinga S, van Doorn J, Veiga SJ, Garcia-Segura LM, Karperien M.

    Department of Pediatrics, Leiden University Medical Center, Leiden, The Netherlands. s.van_gool @ lumc.nl
    Abstract

    Background: Estrogen deficiency induced by aromatase inhibitors may be a novel treatment modality for growth enhancement in short children, but may have adverse effects on bone, brain and reproduction. Aim: To assess growth effects and potential adverse effects of aromatase inhibition in male rats. Methods: 26-day-old prepubertal rats received intramuscular injections with placebo or the aromatase inhibitor exemestane at a dose of 10, 30 or 100 mg/kg/week [E10, E30, E100(6)] for 6 weeks, completely covering the sexual maturation phase, or with 3 weeks E100 followed by 3 weeks placebo [E100(3)]. Growth parameters and histology of the testis, seminal vesicle and brain were analyzed. Bone architecture was studied with X-ray microtomography. Results: Exemestane dose-dependently decreased body weight and tail length gain, as well as liver and seminal vesicle weights, but did not affect nose-anus length gain, growth plate width or radial growth. E100(6) decreased trabecular thickness (epiphysis and metaphysis) and number (metaphysis). Normal IGF-I levels and brain, testis and seminal vesicle morphology were observed. E100(3) resulted in decreased tail length gain only. Conclusion: Exemestane treatment during sexual maturation did not augment linear growth in male rats, but caused impaired body weight and tail length gain and osteopenia.

source


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## heavyiron (Jan 24, 2011)

That is a hefty dose of Aromasin. Not sure I have ever heard of a dose that high.

_"exemestane at a dose of 10, 30 or 100 mg/kg/week"_

1,000mg aromasin a week for a 222lb male??? And that is using their lowest dose.


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## Buzzard (Jan 24, 2011)

heavyiron said:


> That is a hefty dose of Aromasin. Not sure I have ever heard of a dose that high.
> 
> _"exemestane at a dose of 10, 30 or 100 mg/kg/week"_
> 
> 1,000mg aromasin a week for a 222lb male??? And that is using their lowest dose.


 
Who could afford that dose? LOL


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## gsxrguy (Jan 24, 2011)

I knew I was doin myself some good never running an AI during or after a cycle. Nolva and clomid are all that's needed IMO even tho I do keep adex on hand just incase


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## heavyiron (Jan 24, 2011)

gsxrguy said:


> I knew I was doin myself some good never running an AI during or after a cycle. Nolva and clomid are all that's needed IMO even tho I do keep adex on hand just incase


 There are major flaws in this study. They absolutely *anihilated* E2 with the dosing.


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## colorado (Jan 24, 2011)

Just about any substance would be anti-anabolic in massive doses like this study shows.


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## blazeftp (Jan 24, 2011)

heavyiron said:


> That is a hefty dose of Aromasin. Not sure I have ever heard of a dose that high.
> 
> _"exemestane at a dose of 10, 30 or 100 mg/kg/week"_
> 
> 1,000mg aromasin a week for a 222lb male??? And that is using their lowest dose.



I am 10lb short of that weight.

Jesus....i run 12.5mg and my joints start hurting like fuck !


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## gsxrguy (Jan 24, 2011)

heavyiron said:


> There are major flaws in this study. They absolutely *anihilated* E2 with the dosing.


I'm sure u more than correct....however I watch my bros use AI cuz they freak on every nipple itch and bloat and they over kill and I see their strength suffer for it. Unless ur cutting my opinion is don't touch it unless ya have to you should know yourself well enough to know when your estrogen levels are up too high and a lil bit of nolva will handle that.


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## james-27 (Jan 24, 2011)

I'm running Aromasin at 12.5 ED. I'm in week 2 day 1 and up 3 LBS. So far no joint pain and strength "seems" to be up a littler. different people react differently i guess. Then again its really to early to tell if I'm going to supper weight/strength gains.


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## heavyiron (Jan 24, 2011)

gsxrguy said:


> I'm sure u more than correct....however I watch my bros use AI cuz they freak on every nipple itch and bloat and they over kill and I see their strength suffer for it. Unless ur cutting my opinion is don't touch it unless ya have to you should know yourself well enough to know when your estrogen levels are up too high and a lil bit of nolva will handle that.


 Nolva raises circulating estrogen in males.

I think this study just proves that you need SOME E2 for growth but how much is not studied. In other words a guy using a moderate dose of an AI can still get the same growth as a guy not using an AI but the guy on the AI has less risk of female sides from high E2.


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## ROID (Jan 24, 2011)

gsxrguy said:


> I'm sure u more than correct....however I watch my bros use AI cuz they freak on every nipple itch and bloat and they over kill and I see their strength suffer for it. Unless ur cutting my opinion is don't touch it unless ya have to you should know yourself well enough to know when your estrogen levels are up too high and a lil bit of nolva will handle that.



Elevated estrogen levels cause a lot of problems that are not worth having, especially concerning the prostate.

Being able to push a few more pounds on bench press isn't worth it to me. AI cause my joints to ache a little but its worth it.

Nolvadex does nothing to control the increase in estrogen.


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## Glycomann (Jan 24, 2011)

heavyiron said:


> There are major flaws in this study. They absolutely *anihilated* E2 with the dosing.



Enormous dose but one confounding thing about rat studies is they metabolize certain drugs much much faster than humans.  Might be a good idea to look at some other articles to see what doses of exemastane were used in those studies. Also, in general bodybuilders take AI doses that get their E into normal range.  I doubt that would cause suck an anti-anabolic effect.


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## heavyiron (Jan 24, 2011)

Glycomann said:


> Enormous dose but one confounding thing about rat studies is they metabolize certain drugs much much faster than humans. Might be a good idea to look at some other articles to see what doses of exemastane were used in those studies. *Also, in general bodybuilders take AI doses that get their E into normal range. I doubt that would cause an anti-anabolic effect*.


 
Agreed


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## AmM (Jan 25, 2011)

gsxrguy said:


> I knew I was doin myself some good never running an AI during or after a cycle. Nolva and clomid are all that's needed IMO even tho I do keep adex on hand just incase



Unless you are susceptible to gyno. I have to incorporate an AI into every cycle always.


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## gsxrguy (Jan 25, 2011)

ROID said:


> Elevated estrogen levels cause a lot of problems that are not worth having, especially concerning the prostate.
> 
> Being able to push a few more pounds on bench press isn't worth it to me. AI cause my joints to ache a little but its worth it.
> 
> Nolvadex does nothing to control the increase in estrogen.



Ok I must need to do more research. If nolva does nothing to decrease estrogen levels then why is it used as pct?  Please explain to me the error of my ways cuz its worked great so far never had a crash or gyno symptom one.


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## Glycomann (Jan 25, 2011)

gsxrguy said:


> Ok I must need to do more research. If nolva does nothing to decrease estrogen levels then why is it used as pct?  Please explain to me the error of my ways cuz its worked great so far never had a crash or gyno symptom one.



Tamoxifen is a selective estrogen modulator.  It binds to estrogen receptors in some tissues and not others.  It actually acts as an ER agonist in some tissues and an antagonist in others.  In breast tissue it is an ER antagonist meaning that it binds the receptor but does not activate it.  In bone it is an agonist meaning it binds and activates the ER.  It may do little in prostate ER and therefore allow a high estrogen level to do its damage in that tissue such as BPH. Tamoxifen does not directly decrease estrogen. In fact estrogen levels may increase in it's presence as the body senses a lack of E signaling in some tissues. Tamoxifen works in PCT b/c is binds to ER in certain cells in the hypothalamus that are responsible for regulation of GnRH secretion. E is a negative regulator of GnRH secretion. Tamoxifen blocks that negative feedback loop and allows GnRH release leading to LH/FSH secretion from the Pituitary.  Tamoxifen also protects the breast from E signaling so during post cycle it can prevent gynecomastia.


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## rockhardly (Jan 25, 2011)

Glycomann said:


> Tamoxifen is a selective estrogen modulator.  It binds to estrogen receptors in some tissues and not others.  It actually acts as an ER agonist in some tissues and an antagonist in others.  In breast tissue it is an ER antagonist meaning that it binds the receptor but does not activate it.  In bone it is an agonist meaning it binds and activates the ER.  It may do little in prostate ER and therefore allow a high estrogen level to do its damage in that tissue such as BPH. Tamoxifen does not directly decrease estrogen. In fact estrogen levels may increase in it's presence as the body senses a lack of E signaling in some tissues. Tamoxifen works in PCT b/c is binds to ER in certain cells in the hypothalamus that are responsible for regulation of GnRH secretion. E is a negative regulator of GnRH secretion. Tamoxifen blocks that negative feedback loop and allows GnRH release leading to LH/FSH secretion from the Pituitary.  Tamoxifen also protects the breast from E signaling so during post cycle it can prevent gynecomastia.




What the FUCK d'you call me?


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## BigBird (Jan 25, 2011)

Poor rats.  Cute innocent little creatures.


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## ROID (Jan 25, 2011)

gsxrguy said:


> Ok I must need to do more research. If nolva does nothing to decrease estrogen levels then why is it used as pct?  Please explain to me the error of my ways cuz its worked great so far never had a crash or gyno symptom one.



it shouldn't be used in PCT and yes you probably should do more research. 

It does not decrease estrogen.


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## Buzzard (Jan 25, 2011)

heavyiron said:


> Nolva raises circulating estrogen in males.
> 
> I think this study just proves that you need SOME E2 for growth but how much is not studied. In other words a guy using a moderate dose of an AI can still get the same growth as a guy not using an AI but the guy on the AI has less risk of female sides from high E2.


 
Exactly... I don't see 'optimizing' gains as reason to chance gyno and other bad high E2 sides (prostate issues, etc...). The don't get the 'don't take it unless you need it' advice. Scares the sh!t out of me... Waiting for gyno symptoms? Then what... I'm prone to gyno after that? No thanks... I think I can pass on a couple of extra LBM's and maybe a few pounds on my bench to stay safe.


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## BigBird (Jan 25, 2011)

It's all a matter of how much personal risk one is willing to take when deciding whether or not to run an AI.


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## ROID (Jan 25, 2011)

Buzzard said:


> Exactly... I don't see 'optimizing' gains as reason to chance gyno and other bad high E2 sides (prostate issues, etc...). The don't get the 'don't take it unless you need it' advice. Scares the sh!t out of me... Waiting for gyno symptoms? Then what... I'm prone to gyno after that? No thanks... I think I can pass on a couple of extra LBM's and maybe a few pounds on my bench to stay safe.



I developed gyno and I *think *it was because I used Nolva. It developed a few months after the cycle.  Letro done wonders but its still there and surgery is the only way to completely remove it.


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## AmM (Jan 25, 2011)

Buzzard said:


> Exactly... I don't see 'optimizing' gains as reason to chance gyno and other bad high E2 sides (prostate issues, etc...). The don't get the 'don't take it unless you need it' advice. Scares the sh!t out of me... Waiting for gyno symptoms? Then what... I'm prone to gyno after that? No thanks... I think I can pass on a couple of extra LBM's and maybe a few pounds on my bench to stay safe.



Excellent advice!!!


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## gsxrguy (Jan 25, 2011)

Glycomann said:


> Tamoxifen is a selective estrogen modulator.  It binds to estrogen receptors in some tissues and not others.  It actually acts as an ER agonist in some tissues and an antagonist in others.  In breast tissue it is an ER antagonist meaning that it binds the receptor but does not activate it.  In bone it is an agonist meaning it binds and activates the ER.  It may do little in prostate ER and therefore allow a high estrogen level to do its damage in that tissue such as BPH. Tamoxifen does not directly decrease estrogen. In fact estrogen levels may increase in it's presence as the body senses a lack of E signaling in some tissues. Tamoxifen works in PCT b/c is binds to ER in certain cells in the hypothalamus that are responsible for regulation of GnRH secretion. E is a negative regulator of GnRH secretion. Tamoxifen blocks that negative feedback loop and allows GnRH release leading to LH/FSH secretion from the Pituitary.  Tamoxifen also protects the breast from E signaling so during post cycle it can prevent gynecomastia.


Thanx ill def be looking further into this subject you def seem to know ur shit.
Roid: what do you use in pct then?


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## BigBird (Jan 25, 2011)

Yep, I didn't run an AI when I cycled too young at 21 yrs old.  Developed sensitive "breast bud" aka gyno behind left nipple.  Also lactated enough to nurse quadruplets.  Surgery was required so I prefer to run some kind of AI these days.


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## ROID (Jan 25, 2011)

gsxrguy said:


> Thanx ill def be looking further into this subject you def seem to know ur shit.
> Roid: what do you use in pct then?



Clomid Bro.  HI or CT put up a good article about nolvadex. Go to pub med and search. I think that is where it came from.

Using an AI isn't going to hinder your gains that much. don't make the mistake I did and think you can get away with out using one. It will come back to haunt you.

are you running HCG along with your cycle ?


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## heavyiron (Jan 25, 2011)

Buzzard said:


> Exactly... I don't see 'optimizing' gains as reason to chance gyno and other bad high E2 sides (prostate issues, etc...). The don't get the 'don't take it unless you need it' advice. Scares the sh!t out of me... Waiting for gyno symptoms? Then what... I'm prone to gyno after that? No thanks... *I think I can pass on a couple of extra LBM's and maybe a few pounds on my bench to stay safe*.


 
There is no evidence that moderate use of an AI reduces LBM gains or strength. Do we need _some_ E2? Yes, however the amount needed for LBM is very small. 

Proper AI use protects the steroid user and does not negatively affect muscle gains.


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## G3 (Jan 25, 2011)

Question for all you guys especially, Heavy. Is having your blood tested for estrogen levels the best way to get your AI dose right? What do you guys think? It seems like we're all guessing about it instead of knowing for sure.


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## heavyiron (Jan 25, 2011)

G3 said:


> Question for all you guys especially, Heavy. Is having your blood tested for estrogen levels the best way to get your AI dose right? What do you guys think? It seems like we're all guessing about it instead of knowing for sure.


 Absolutely. We need some E2 so I would try to target 25pg/ml.


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## heavyiron (Jan 25, 2011)

Glycomann said:


> Enormous dose but *one confounding thing about rat studies is they metabolize certain drugs much much faster than humans. Might be a good idea to look at some other articles to see what doses of exemastane were used in those studies*. Also, in general bodybuilders take AI doses that get their E into normal range. I doubt that would cause suck an anti-anabolic effect.


 
Btw, this is an excellent point as well. I was in PM with Anthony today and he stated that the doses cannot be calculated mg-kg from rats to humans.

 AR stated "_There's a series of formula, which are based on bodysurface area (BSA), not weight, to determine the human equivalsent dose (HED)"_

I just want to be honest with the data and not paint an incorrect picture. I have always loved Anthony's writings and still follow them to this day.


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## XYZ (Jan 25, 2011)

heavyiron said:


> there are major flaws in this study. They absolutely *anihilated* e2 with the dosing.


 

+1.


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## G3 (Jan 25, 2011)

heavyiron said:


> Absolutely. We need some E2 so I would try to target 25pg/ml.


 

Thanks Bro.


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## cutright (Jan 25, 2011)

I'm running an AI on my first cycle..based off heavyirons cycle suggest...so I don't have a cycle without to compare..but my weight is up and I'm stronger than I've ever been in my life. Prevent is better than treating gyno in my mind...my buddy takes no AI..he's had nipple irritation bad and I'm smoking him in size and strength...I guess that's the only study I need right there.


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## ROID (Jan 25, 2011)

cutright said:


> I'm running an AI on my first cycle..based off heavyirons cycle suggest...so I don't have a cycle without to compare..but my weight is up and I'm stronger than I've ever been in my life. Prevent is better than treating gyno in my mind...my buddy takes no AI..he's had nipple irritation bad and I'm smoking him in size and strength...*I guess that's the only study I need right there.*



lol


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## G3 (Jan 26, 2011)

heavyiron said:


> Absolutely. We need some E2 so I would try to target 25pg/ml.


 

I overlooked the amount last night. Is that 25 picograms per ml? Holy shit that is teeeny. Estrogen must be strong shit.


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## ANIMALHAUS (Jan 26, 2011)

This is the by far the BEST topic post I have ever read on this forum.


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## bknoxx (Jan 26, 2011)

nice read it's to risky with out an AI ...IMO


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