LAWNSAVER
New member
by Bill Roberts,
http://mesomorphosis.com/articles/p...tiestrogens.htm
Because of their ability to reduce risk of gynecomastia (abnormal growth of breast tissue in males) and enhance recovery of natural testosterone production after a cycle, use of antiestrogens such as aminoglutethimide (Cytadren) and clomiphene (Clomid) has become popular in bodybuilding. Antiestrogens also can reduce bloating associated with anabolic/androgenic steroid use, and may avoid health risks associated with elevated estrogen levels. Medically, the drugs are used not only for treatment of breast cancer but also for improvement of fertility in both men and women, and occasionally for increasing testosterone levels in men such as endurance athletes with low testosterone. There are two categories of antiestrogens: aromatase inhibitors and receptor blockers. Both shall be considered here.
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Estrogens
As with androgens, where any hormone that has the activity of testosterone is an androgen and therefore all anabolic steroids are androgens, any hormone that has the activity of estradiol, the principal female sex hormone, is an estrogen. The most active natural estrogens in humans are estradiol and estrone.
These hormones are related to each other rather similarly to how the andro prohormones are related to each other. Just as androdiol has a hydroxy (or –ol) group at both the 3- and 17- positions, estradiol likewise has a hydroxy group at those positions. Estrone, like androstenedione, has keto (or –one, pronounced "oan") groups at those positions.
Estradiol is the most potent (effective per milligram) of the natural estrogens. It is produced either from testosterone via the aromatase enzyme, or from estrone via the estrogenic 17b-HSD enzyme.
Estrone is less potent, but all this means is that one needs more of it to accomplish the same job. It is produced either from androstenedione via aromatase, or from estradiol via the same 17b-HSD enzyme working in reverse.
From the standpoint of the bodybuilder using anabolic/androgenic steroids (AAS), if nothing is done about the situation, high estrogen levels can cause gynecomastia, will inhibit natural testosterone production, and will cause bloating. High estrogen levels also make it more difficult to lose fat, and tend to cause female pattern fat distribution even in males.
Estradiol also has carcinogenic metabolites, and a liver problem sometimes associated with Anabolic Androgenic Steroids (AAS) use, hepatic cholestasis, is caused not by androgen but by an estrogen metabolite.
It is also not unusual for bodybuilders to feel poorly on beginning a cycle of high dose testosterone without antiestrogens, and for this reason many have advocated starting with a low dose and building up. However, I strongly suspect that the real problem is estrogenic effect on mood, and the problem can be avoided with use of an aromatase inhibitor.
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Aromatizable steroids
Though most bodybuilders feel they know which steroids aromatize and which do not, sometimes the beliefs are in error. This is because progestogenic activity (activity like that of progesterone, another female hormone) is easily mistaken for estrogenic activity. Both hormones can cause bloating, and both can cause gyno. So Anabolic Androgenic Steroids (AAS) which are capable of activating not only the androgen receptor but also the progesterone receptor are often mistakenly assumed to aromatize. (Note: these androgens do not "convert to progesterone" but rather are themselves, without any change needed, able to act on that receptor.)
Nandrolone is proven to be a progestin. This fact is of clear importance in bodybuilding, because while moderate Deca-only use actually lowers estrogen levels as a consequence of reducing natural testosterone levels and thus allowing the aromatase enzyme less substrate to work with, Deca nonetheless can cause gyno in some individuals. Furthermore, just as progesterone will to a point increase sex drive in women, and then often decrease it as levels get too high, high levels of progestogenic steroids can kill sex drive in male bodybuilders, though there is a great deal of individual variability as to what is too much.
Incidentally, this progestogenic activity also inhibits LH production, and contrary to common belief, even small amounts of Deca are quite inhibitory, approximately as much so as the same amount of testosterone.
What relevance does this have to an article on antiestrogens? Well, antiestrogens can do nothing about these side effects of Deca.
The same appears to be true of oxymetholone (Anadrol) and of norethandrolone (Nilevar).
Methenolone (Primobolan), stanozolol (Winstrol), dromostanolone (Masteron), oxandrolone (Anavar), mesterolone (Proviron), stenbolone (Anatrofin), trenbolone, and DHT do not aromatize, and thus, antiestrogens are not relevant to these Anabolic Androgenic Steroids (AAS) either.
The steroids where aromatization is of particular concern are testosterone, methandrostenolone (Dianabol), boldenone (Equipoise), and to some extent fluoxymesterone (Halotestin). However the latter is usually used in doses low enough that aromatization is not an issue.
Among the prohormones, androstenedione is the principal offender with regard to aromatization, being readily converted to estrone. With androdiol, only that small portion which converts to testosterone can be converted further to estradiol, and that will occur only in the same percentage that other testosterone converts to estradiol.
Norandrodiol cannot convert directly to estrogen, and even after conversion to nandrolone is not readily converted to estrogen.
Norandrostenedione can be converted to estrone by aromatase, but is a very poor substrate for that enzyme. It can actually act as a competitive inhibitor, blocking better substrates such as androstenedione or testosterone. It is possible then, though unproven, that norandrostenedione might have some value as an aromatase inhibitor in bodybuilding. I do think, however, that the pharmaceuticals designed for the purpose should be assumed to be better choices.
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Aromatase inhibitors
The most commonly used aromatase inhibitor in bodybuilding is aminoglutethimide (Cytadren). This drug also inhibits an enzyme (desmolase) necessary for synthesis of cortisol, but fortunately, aromatase can be inhibited with levels of drug that cause only limited inhibition of desmolase.
Contrary to popular belief, it is generally not desirable to inhibit cortisol production. Doing so will likely lead to joint problems, and furthermore once the inhibition ends, the price of above-normal cortisol production must usually be paid.
For an average male, a dose of 250 mg/day (one tablet) appears optimal. The half-life is 8 hours, so the drug is better taken in divided doses. The best plan seems to be to take half a tablet on arising, and quarter tabs six and twelve hours later. This keeps levels generally fairly constant, but allows a small drop in the hours shortly before arising, which is then compensated for by the higher dose on arising. With this scheme, inhibition of cortisol production is generally too low to be noticed, and generally there is no rebound effect on discontinuance. However it is not a bad idea nonetheless to taper off, first omitting the midday quarter tab dose for a few days, then omitting both quarter tab doses, then reducing the initial dose to one quarter tab, and then ending completely. A week is sufficient for the taper.
Some people suffer a degree of lethargy or sedation from aminoglutethimide, even at this low dose, but most do not.
Anastrozole (Arimidex) is a superior aromatase inhibitor which does not have the above side effects. It is, however, very expensive. With moderate doses of testosterone it seems that 1 mg/day is sufficient, and some have claimed half a tab to be sufficient. I do not have blood test data to verify that, however.
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http://mesomorphosis.com/articles/p...tiestrogens.htm
Because of their ability to reduce risk of gynecomastia (abnormal growth of breast tissue in males) and enhance recovery of natural testosterone production after a cycle, use of antiestrogens such as aminoglutethimide (Cytadren) and clomiphene (Clomid) has become popular in bodybuilding. Antiestrogens also can reduce bloating associated with anabolic/androgenic steroid use, and may avoid health risks associated with elevated estrogen levels. Medically, the drugs are used not only for treatment of breast cancer but also for improvement of fertility in both men and women, and occasionally for increasing testosterone levels in men such as endurance athletes with low testosterone. There are two categories of antiestrogens: aromatase inhibitors and receptor blockers. Both shall be considered here.
--------------------------------------------------------------------------------
Estrogens
As with androgens, where any hormone that has the activity of testosterone is an androgen and therefore all anabolic steroids are androgens, any hormone that has the activity of estradiol, the principal female sex hormone, is an estrogen. The most active natural estrogens in humans are estradiol and estrone.
These hormones are related to each other rather similarly to how the andro prohormones are related to each other. Just as androdiol has a hydroxy (or –ol) group at both the 3- and 17- positions, estradiol likewise has a hydroxy group at those positions. Estrone, like androstenedione, has keto (or –one, pronounced "oan") groups at those positions.
Estradiol is the most potent (effective per milligram) of the natural estrogens. It is produced either from testosterone via the aromatase enzyme, or from estrone via the estrogenic 17b-HSD enzyme.
Estrone is less potent, but all this means is that one needs more of it to accomplish the same job. It is produced either from androstenedione via aromatase, or from estradiol via the same 17b-HSD enzyme working in reverse.
From the standpoint of the bodybuilder using anabolic/androgenic steroids (AAS), if nothing is done about the situation, high estrogen levels can cause gynecomastia, will inhibit natural testosterone production, and will cause bloating. High estrogen levels also make it more difficult to lose fat, and tend to cause female pattern fat distribution even in males.
Estradiol also has carcinogenic metabolites, and a liver problem sometimes associated with Anabolic Androgenic Steroids (AAS) use, hepatic cholestasis, is caused not by androgen but by an estrogen metabolite.
It is also not unusual for bodybuilders to feel poorly on beginning a cycle of high dose testosterone without antiestrogens, and for this reason many have advocated starting with a low dose and building up. However, I strongly suspect that the real problem is estrogenic effect on mood, and the problem can be avoided with use of an aromatase inhibitor.
--------------------------------------------------------------------------------
Aromatizable steroids
Though most bodybuilders feel they know which steroids aromatize and which do not, sometimes the beliefs are in error. This is because progestogenic activity (activity like that of progesterone, another female hormone) is easily mistaken for estrogenic activity. Both hormones can cause bloating, and both can cause gyno. So Anabolic Androgenic Steroids (AAS) which are capable of activating not only the androgen receptor but also the progesterone receptor are often mistakenly assumed to aromatize. (Note: these androgens do not "convert to progesterone" but rather are themselves, without any change needed, able to act on that receptor.)
Nandrolone is proven to be a progestin. This fact is of clear importance in bodybuilding, because while moderate Deca-only use actually lowers estrogen levels as a consequence of reducing natural testosterone levels and thus allowing the aromatase enzyme less substrate to work with, Deca nonetheless can cause gyno in some individuals. Furthermore, just as progesterone will to a point increase sex drive in women, and then often decrease it as levels get too high, high levels of progestogenic steroids can kill sex drive in male bodybuilders, though there is a great deal of individual variability as to what is too much.
Incidentally, this progestogenic activity also inhibits LH production, and contrary to common belief, even small amounts of Deca are quite inhibitory, approximately as much so as the same amount of testosterone.
What relevance does this have to an article on antiestrogens? Well, antiestrogens can do nothing about these side effects of Deca.
The same appears to be true of oxymetholone (Anadrol) and of norethandrolone (Nilevar).
Methenolone (Primobolan), stanozolol (Winstrol), dromostanolone (Masteron), oxandrolone (Anavar), mesterolone (Proviron), stenbolone (Anatrofin), trenbolone, and DHT do not aromatize, and thus, antiestrogens are not relevant to these Anabolic Androgenic Steroids (AAS) either.
The steroids where aromatization is of particular concern are testosterone, methandrostenolone (Dianabol), boldenone (Equipoise), and to some extent fluoxymesterone (Halotestin). However the latter is usually used in doses low enough that aromatization is not an issue.
Among the prohormones, androstenedione is the principal offender with regard to aromatization, being readily converted to estrone. With androdiol, only that small portion which converts to testosterone can be converted further to estradiol, and that will occur only in the same percentage that other testosterone converts to estradiol.
Norandrodiol cannot convert directly to estrogen, and even after conversion to nandrolone is not readily converted to estrogen.
Norandrostenedione can be converted to estrone by aromatase, but is a very poor substrate for that enzyme. It can actually act as a competitive inhibitor, blocking better substrates such as androstenedione or testosterone. It is possible then, though unproven, that norandrostenedione might have some value as an aromatase inhibitor in bodybuilding. I do think, however, that the pharmaceuticals designed for the purpose should be assumed to be better choices.
--------------------------------------------------------------------------------
Aromatase inhibitors
The most commonly used aromatase inhibitor in bodybuilding is aminoglutethimide (Cytadren). This drug also inhibits an enzyme (desmolase) necessary for synthesis of cortisol, but fortunately, aromatase can be inhibited with levels of drug that cause only limited inhibition of desmolase.
Contrary to popular belief, it is generally not desirable to inhibit cortisol production. Doing so will likely lead to joint problems, and furthermore once the inhibition ends, the price of above-normal cortisol production must usually be paid.
For an average male, a dose of 250 mg/day (one tablet) appears optimal. The half-life is 8 hours, so the drug is better taken in divided doses. The best plan seems to be to take half a tablet on arising, and quarter tabs six and twelve hours later. This keeps levels generally fairly constant, but allows a small drop in the hours shortly before arising, which is then compensated for by the higher dose on arising. With this scheme, inhibition of cortisol production is generally too low to be noticed, and generally there is no rebound effect on discontinuance. However it is not a bad idea nonetheless to taper off, first omitting the midday quarter tab dose for a few days, then omitting both quarter tab doses, then reducing the initial dose to one quarter tab, and then ending completely. A week is sufficient for the taper.
Some people suffer a degree of lethargy or sedation from aminoglutethimide, even at this low dose, but most do not.
Anastrozole (Arimidex) is a superior aromatase inhibitor which does not have the above side effects. It is, however, very expensive. With moderate doses of testosterone it seems that 1 mg/day is sufficient, and some have claimed half a tab to be sufficient. I do not have blood test data to verify that, however.
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