T-man Vs. E-man

The Armory: Anti-Estrogens and Aromatase Inhibitors

High atop the city's tallest skyscraper, the epic battle between good and evil rages o

"Take this, blue boy!" giggles E-man as he whips aside his pink cape to reveal a utility belt filled with foam-covered pastel dumbbells.

"Bring it on," mutters T-man.

The arch nemesis E-man, sporting both the musculature and the breasts of a chubby 14 year-old girl, flings the deadly polyurethane projectiles at T-man... all of which land harmlessly at our hero's feet.

"Wow, you even throw like a girl," says T-man, "Is that all you've got?"

"I'll show you," E-man lisps. He reaches into the back of his lacey cape and brings forth his most vile creation, the dreaded soy gun. "Prepare to die!" E-man says as he pulls the trigger, "Or at least to really start liking N'Sync!"

But T-man isn't phased. He quickly drops his pants and begins whirling his mighty Rod of Justice through the air, building up speed. Whoosh. Whoosh. Whoosh-whoosh-whoosh. In a nanosecond, he creates a powerful wind that catches the deadly stream of soy in midair and turns it back from whence it came.

His maniacal weapon turned against him, E-man is buried alive in a mound of soy protein. Triumphant, T-man reels in the Rod of Justice. "Let that be a lesson to you, E-man. Testosterone will always defeat estrogen, if you have the right tools."

Tune in next week, as our hero does battle with Angela the Aerobics Instructor and her evil hoard of Guys Who Curl in the Squat Rack.

Okay, maybe that's taking the war on estrogen a little too far. But if you're a man who wants to remain that way and maybe experiment with a few anabolics, then estrogen should be a major concern. We've asked our own caped crusader, Cy Willson, to provide an overview of the various pharmacological weapons against estrogen.

In the world of bodybuilding, opinions vary on everything from what protein to consume, which type of fat you should be swallowing, which training protocol you should follow, and even whether you should spank the frank before or after training. Well, at least there's one consensus: Estrogen isn't something male bodybuilders want to deal with.

To be more specific, those that use anabolic steroids that can aromatize and therefore increase estrogen levels have to deal with a number of problems. Mainly, the effects on the prostate via estrogen and developing breast tissue (gynecomastia, or "bitch tits"). The solution is to use compounds that act to prevent estrogen from binding to receptor sites or that actually prevent estrogen from being formed by inhibiting the enzyme (aromatase) that's responsible for its conversion.

In most cases, these compounds can also help to raise your endogenous Testosterone levels after a cycle has been completed and can even help to prevent testicular atrophy in the first place. In the following article, I'm going to compare some of the most common compounds of this nature and explain how they work.


Here's how anti-estrogens and aromatase inhibitors work. Anti-estrogens, in general, bind to the ER (estrogen receptor) and prevent estrogen from binding. The anti-estrogens themselves don't initiate any transcription, or at least very little.

Here's an analogy I like to use. Say you have a door and you need to open it. Well, this is analogous to a hormone carrying out a specific effect. Now, to open this door, you need a key hole (the receptor), but the only way you can open it, of course, is with the proper key (a hormone, like estrogen). So in the case of gyno, estrogen (the key) binds to alpha receptors (the key hole) on breast tissue and causes growth (the door opening). So, if you wanted to prevent this from happening, you'd use a key that could fit in the hole, but wouldn't actually allow the door to open. In other words, it's like a dummy key. This is how anti-estrogens work.

Aromatase inhibitors, on the other hand, work in a different manner. They actually prevent estrogen from being formed. So, this would be like going to the key shop and kicking the crap out of the key maker. If no key is present, the door can't be opened and hence, no adverse effects on the prostate or breast tissue formation.

Here's a run down of these drugs along with some other pertinent info:

Clomiphene (Clomid, Serophene, Omifin)

Clomiphene was originally developed to help treat female infertility caused by ovulatory dysfunction. It works in women by binding competitively to estrogen receptors on the hypothalamus and pituitary. This causes an increased secretion of leutinizing hormone-releasing hormone as well as follicle-stimulating hormone-releasing hormone which in turn causes a release of LH and FSH. Did you follow that? These two hormones play key roles in the process of ovulation and maturation of the ovarian follicle, which is necessary to make a baby.

So, what the hell does this have to do with a bodybuilder? I'm sure most of you are already familiar with what I'm about to tell you. That is, clomiphene, which increases LH and FSH in women, can do the same in men. As we all know, LH is responsible for endogenous Testosterone production in men. This is a great thing for guys who've just come off a cycle which has shut down or limited the production of their endogenous T.

So, what else is great about this stuff? Well, you should also notice that while it binds to estrogen receptors on the hypothalamus and pituitary, it does the same with breast tissue. When it does, this prevents endogenous estrogen from binding to the alpha receptor sites. The alpha receptors are those found with breast tissue.

What else? Well, it can improve blood lipid profiles to some extent. This is thought to be an inherent property of all anti-estrogens. It's thought to occur because of clomiphene's estrogen-like influence on the cardiovascular system, lowering low density lipoproteins in the plasma (1).

Oh, and one more thing. Yes, clomiphene has been shown to increase LH and Testosterone, both total and free in normal and oligospermic men (dudes with low sperm count). But what about in men that have exercise-induced hypogonadism? The answer is that clomiphene can help them as well.

In one study, a 29-year-old male runner had reached a state of hypogonadism from overtraining, something that's also commonly seen amongst bodybuilders. He received 50 mg of clomiphene daily for five weeks and afterward, reached normal levels of LH, FSH, and Testosterone, both free and total. After four months of treatment, improvements were seen in muscle strength, daily morning erections, sense of well being, and energy (2).

I think it can be concluded that clomiphene is very effective at increasing LH and Testosterone levels. It's good at preventing gynecomastia and can also improve blood lipid profiles.

So what dosages should be used? For the LH/Testosterone boosting effect, a dosage of 50 to100 mg per day. When using it as an anti-estrogen, you should employ larger dosages. Depending on what steroid you're using and how much, you should use 50 to 300 mg per day during the cycle. It's been shown that clomiphene is more effective for preventing and treating gynecomastia when higher dosages are used (3).

If you're getting it the legit way, through your doctor, the price for the brand name Clomid is around nine to ten bucks per tab. The generic version is around four dollars per tab. Of course, a little bird told me that the street price is much lower and that many of the same, uh, business men, who sell steroids will sell clomiphene for around fifty cents to a dollar per tab.

Tamoxifen (Nolvadex)

Tamoxifen is also an anti-estrogen. It started out as a means of treatment for breast cancer. Tamoxifen works in a similar fashion to that of clomiphene in that it binds competitively to estrogen receptors throughout the body. It especially binds well to the alpha receptor that can promote breast tissue growth. It, like clomiphene, can increase LH and Testosterone, but not to the same extent.

One could guess that by using a higher amount of tamoxifen, you could achieve the same LH boosting effects as those seen with clomiphene. However, in one study, no difference was found in terms of LH and Testosterone levels when men were given either 5 or 10 mg daily or 20 mg daily (4). If, however, these levels were increased even higher to 40 to 80 mg, the results may have been different. For now though, I'd say clomiphene is the better of the two in terms of elevating LH and Testosterone.

What else is good about tamoxifen? It's been shown to be beneficial to blood profiles by lowering LDL (5). It also has antioxidant properties as well as anti-yeast/viral effects. Last but not least, it's been shown to be very effective at treating gynecomastia. With dosages of 40 mg per day it was shown to be effective in 80% of men with gyno. A dosage of 10 to 20 mg was also shown to be effective. (6,7) Personally, I'd use 20 to 40 mg per day if I wanted to prevent gyno. For an elevation in LH, however, I'd use around 80 to 100 mg per day. The half life of tamoxifen is five to seven days.

The cost for Nolvadex is around $1.80 per tablet while the generic brand is about twenty cents cheaper.

Raloxifene (Evista)

This drug was originally approved for the treatment and prevention of osteoporosis in postmenopausal women. Yep, yet another chick drug. Raloxifene has agonistic properties on bone. That means it acts in a similar fashion to estrogen by binding to the Beta version of the ER and inducing transcription. This is a good thing.

As a matter of fact, clomiphene and tamoxifen do this as well, but not to the same extent, it seems. What they found later about this substance was that it also has antagonistic effects on the ER alpha in humans. Thus, it could be used as an alternative to tamoxifen.

Like the other two drugs, raloxifene can also lower LDL levels because of its agonistic effects on lipid metabolism. Is it beneficial to LH and Testosterone levels? It seems as though it is, but not to a very great extent; perhaps less than that of tamoxifen. (8) So, if you're after it for a means of preventing gyno, I'd say a dosage of 60 to 240 mg is necessary. For a possible elevation of endogenous Testosterone, higher dosages would need to be used, possibly 200 to 300 mg per day. The half life is 27.7 hours. The cost is about $2.25 to $3 per 60mg tab.

Testolactone (Teslac)

This is the first of the aromatase inhibitors that I'll discuss. This drug is also used in the treatment of postmenopausal breast cancer. It's a synthetic derivative of Testosterone but lacks any real androgenic effects. As mentioned previously, it works by inhibiting aromatase activity, thus blocking any formation of estradiol and estrone from Testosterone or androstenedione. While it doesn't appear to have significant effects on LH, a 30% increase in Testosterone has been demonstrated.(9,10,11)

Still, it wouldn't be the best choice for an elevation of Testosterone. If you were to use it for its estrogen suppressing effects, the typical dose is 250 mg four times per day. One downfall of this drug that should be noted is its short half life, which is the reason for frequent dosing. The cost is around $2.25 to $3 per tab.

Formestane (Lentaron Depot)

This drug is an androstenedione analog that inhibits aromatase activity. It's been used to treat postmenopausal breast cancer as well. Formestane is a fairly potent drug in regard to its inhibition of aromatase activity. When compared to testolactone and aminoglutethimide, it was found to be 500 and 1,000 times more potent, respectively. This was in vitro, however, which isn't always directly correlative with what will actually happen in the body.(12) Still, it's highly likely that formestane is indeed superior.

As far as an LH/Testosterone elevation is concerned, it has some merit. It's been shown to slightly increase androgen levels in healthy males.(13) The only problem, as I see it, would be the need to inject the drug every two weeks as the half life is five to ten days. This may prove to be cumbersome for some people. While you could take the drug orally, the half life decreases to around two to three hours, so I don't think it would be worth it. Still, it's advantageous over drugs like Cytadren because of its higher selectivity, meaning it doesn't have that great of an effect on other enzymatic systems.

With that being said, the dosing regimen is as follows. For lowering estrogen levels, 250 to 500 mg every two weeks. If you'd like to try elevating androgen levels, you could try 250 mg every two weeks and see how that works. Still, I wouldn't use it for an LH/Testosterone elevation. Arimidex is probably the only one worthy in that regard.

The cost I don't have. This is because you'll have to order it from Europe if you wish to try it. I've heard that it's quite expensive, though.

Aminoglutethimide (Cytadren)

This drug is used to treat breast cancer in women, as well as Cushing's Syndrome, a hormonal disorder that includes an overproduction of cortisol. The big problem with using this drug as a means of reducing estrogen is that it isn't very selective in terms of which enzymes it affects. Not only does it inhibit the conversion of Testosterone to estrogen, but it does the same with the conversion of cholesterol to pregnenolone in the adrenal glands. This leads to a dramatic reduction in cortisol production.

"Sign me up!" most guys will respond, but hold on a minute. This may seem good at first, but when you suppress cortisol levels like this, they tend to "rebound" after cessation of use. When this occurs, the person often displays symptoms of Cushing's Syndrome, which includes things like a puffy face, higher body fat around the upper body, loss of muscle tissue, and general muscle weakness. Also, if you use it long enough, you can suppress thyroid levels as well.

I really don't see the purpose of using this drug when more potent and selective drugs are available. I'd prefer that you not use it at all. If you're going to use it anyway, I wouldn't go above 500 mg per day. The half life is around nine to thirteen hours which is why more frequent dosing is required. Aminoglutethimide will run you around $1.75 to $2.00 per 250 mg tab.

Anastrozole (Arimidex)

This drug is also used to treat breast cancer in post-menopausal women. It's a very potent and selective inhibitor of aromatase activity and it's the most effective of all the current aromatase inhibitors available on the market. Anastrozole can reduce estrogen to undetectable levels in men. It doesn't have any effect on other enzymes because it's so selective, thereby leaving hormones like cortisol, aldosterone, and thyroid at normal levels.

One in vitro study compared the effectiveness of anastrozole to aminoglutethimide and formestane. Anastrozole was found to be 200 times more potent than aminoglutethimide and was more than three times more effective than formestane.(14) The superiority of anastrozole to formestane has also been demonstrated in vitro as well. Patients were given either 250 mg injections every two weeks with formestane or took a 1 mg tablet of anastrozole per day. Estrogen levels were measured after four weeks. Anastrozole reduced serum estradiol levels by 21% more than formestane. Estrone was reduced by 18% more with anastrozole. (15)

So what about using this drug for an LH/Testosterone boost? In normal men, it was shown that 1 mg per day increased LH by 100% and Testosterone levels by 53-58%.(16,17) There's been talk that this drug may lower estrogen levels too low and thus cause some adverse effects. One such effect would be an increase in LDL levels. However, the elevations that were seen were very small and thus wouldn't be something to concern yourself with. Just remember that they've found little difference between using 1 mg or 10 mg, so the "more is better" approach doesn't apply.

If you wish to use this for estrogen suppression, try .5 to 1 mg per day. For an elevation of LH/Testosterone, try 1 mg per day. The cost of the drug is around $6.50 per tab.

To sum things up, I'd like to give you a chart with a rating of each drug in a few categories. The rating range is from one to five with five being best.








Per Effective Unit

Clomiphene 3 5 * 5**
Tamoxifen 4 4 * 4
Raloxifene 3 3 * 3
Testolactone 4 2 4 1.5
Formestane 4.5 2 4.5 1
Aminoglutethimide 4 1 4 5
Anastrozole 5 3.75 5 3.5

*These drugs prevent estrogen from binding but do not actually reduce the amount of estrogen production.

**I realize that with this and every other drug on this list, the pharmacy and "street" prices will vary significantly. Knowing that clomiphene is so cheap on the black market, I had to give it a great cost rating. I'd also like to note that Arimidex isn't that expensive when you consider how little you need for it to work.


Like I've said in previous articles, the best two choices would be clomiphene and Anastrozole. If you'd like to get your endogenous Testosterone levels back to normal, clomiphene seems to be the best choice and it also has the benefit of preventing gyno provided that the dosages are sufficient. If you want to actually reduce your estrogen levels, then take anastrozole instead. You get the added benefit of an increased LH/Testosterone levels as well.

If you don't wish to wipe out estrogen levels, but still want to have superior anti-gyno action, then tamoxifen would be your choice. It's also relatively cheap. Still, it's always best to make your own decision. Pick your weapon and head out for battle, guys!


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3. Le Roith D, et al. "The effect of clomiphene citrate on pubertal gynecomastia." Acta Endocrinologica 1980; 95:177

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9. Dony JM, et al. "Effect of chronic aromatase inhibition by delta 1-testolactone on pituitary-gonadal function in oligozoospermic men." Andrologia 1986 Jan-Feb;18(1):69-78

10. Dony JM, et al. "Effect of aromatase inhibition by delta 1-testolactone on basal and luteinizing hormone-releasing hormone-stimulated pituitary and gonadal hormonal function in oligospermic men." Fertil Steril 1985 May;43(5):787-92

11. Martikainen H, et al. "Short-term effects of testolactone on human testicular steroid production and on the response to human chorionic gonadotropin." Fertil Steril 1985 May;43(5):793-8

12. Wiseman LR, McTavish D. "Formestane. A review of its pharacodynamic and pharmacokinetic properties and therapeutic potential in the management of breast cancer and prostatic cancer." Drugs 1993; 45:66-84

13. Dowsett M, Llyod P. "Comparison of the pharmacokinetics and pharmacodynamics of unformulated and formulated 4-hydroxyandrostenedione taken orally by healthy men." Cancer Chemother Pharmacol 1990; 27:67-71

14. Miller WR. "Aromatase inhibitors – where are we now?" British J Anaesthesia 1996; 4:415-417

15. Vorobiof DA, et al. "A randomized, open, parallel-group trial to compare the endocrine effects of oral anastozole (Arimidex ®) with intramuscular formestane in postmenopausal women with advanced breast cancer." Ann Oncol 1999; 10:1219-1225

16. Hayes FJ, et al. "Aromatase inhibition in the human male reveals a hypothalamic site of estrogen feedback." J Clin Endocrinol Metab 2000 Sep;85(9):3027-35

17. Mauras N, et al. "Estrogen suppression in males: metabolic effects." J Clin Endocrinol Metab 2000 Jul;85(7):2370-7