Anti estrogen drugs not only help minimize side effects while on a steroid cycle, they are also extremely important in post cycle therapy.
Anti Estrogen Drugs
Anti Estrogen Drugs are used to reduce the estrogenic activity in the body. The drugs either reduce the estrogen or reduce the activity of the estrogen. Aromatase inhibitors work by inhibiting the action of the enzyme aromatase, which converts androgens into estrogens by a process called aromatization. In regards to anabolic steroids, they bind to the same binding site on the aromatase enzyme that testosterone does. In turn, less testosterone is converted to estrogen.
Arimidex (Anastrozole) is what we call an aromatase inhibitor (AI). In clinical use, it´s used to halt the progression of Breast Cancer in women. It works by blocking the aromatase enzyme, which is responsible for the production of estrogen. In athletics and bodybuilding, it is used as an ancillary compound to be added to a cycle of Anabolic Steroids. In this respect it is also used for its estrogen reducing properties, but it has the additional benefit of increasing testosterone levels, as we´ll see...
Arimidex Side Effects
Many anabolic steroids aromatize (convert to estrogen via the aromatase enzyme), and this is responsible for many of the unwanted side effects found with anabolic steroid use (acne, gynocomastia, water-retention, etc...). In one study, both .5mg and 1mg doses of Arimidex were shown to decrease estrogen by roughly 50%. The 1mg/day dose also increased testosterone levels by 58% (1). In that same study, in both groups, LH and FSH also went up slightly.
Take a look:
Changes in testosterone and E2 concentrations in normal young men (15 22 yr old) before () and after 10 days of oral anastrozole at 0.5 and 1 mg.(1)
This would seem to suggest that for use during a cycle, a dose of .5mgs/day would be sufficient to combat estrogen-related side effects. It is, however, important to remember that some estrogen is necessary to obtain optimal muscle growth. The lower estrogen levels provided by ´dex seems, anecdotally at least, to produce a more "hard" and "quality" look for bodybuilders who have experimented with it´s use in either a cutting or bulking cycle.
I´d like to point out that the elevation in Testosterone provided by Arimidex is so large that it can be used as a "form" of testosterone replacement therapy for hypogonadal men (2). Clearly, this suggests its use in a post-cycle-therapy (as well as its previously discussed use within a cycle) to regain natural testosterone levels and full functioning of the HPTA (Hypothalamic-Testicular-Pituitary-Axis).
Literature provided by the original maker of Anastrozole (Arimidex, produced by Zeneca Pharmaceuticals) states that stable blood plasma concentrations of the compound are achieved after a mere 7 consecutive 1mg daily doses. Also, Arimidex is just over 80% effective at inhibiting aromatase (3). Thus, if you want to take it for the entire duration of a cycle of anabolic steroids, you can simply start taking it on the same day you begin your cycle. Those are some pretty good numbers, huh?
But can you use it for the entire duration of a cycle? Is it dangerous? Well, certainly reducing estrogen levels in your body is good from a body building point of view, as it reduces water-retention and the potential for gynocomastia (if there´s no estrogen in your body, you can´t get gyno, regardless of how much progesterone is floating around)(5). Luckily this stuff is very mild on blood lipids (cholesterol) and doesn´t affect them adversely (2), in the studies I´ve seen.
Arimidex and Cholestrol
As previously mentioned, those lowered estrogen levels could possibly (eventually) adversely affect your cholesterol and possibly even your immune function. I am, however, very comfortable recommending Arimidex for relatively long-term use. This should be the ancillary compound of choice for those on long and heavy cycles, especially since it also doesn´t inhibit igf like some other ancillary compounds (insulin-like-growth-factor is an important component of anabolism)(4).
Chemical Name: Femara
Drug Class: Type-II Aromatase Inhibitor
Letrozole is Novartis’ entry into the breast cancer treatment world. It’s a Type-II Aromatase Inhibitor (AI), which means that it competitively binds to the aromatase enzyme and inhibits the enzyme’s ability to metabolize testosterone into estrogen. This drug was developed to fight breast cancer by inhibiting the aromatization.
Letrozole is probably the most powerful Aromatase Inhibitor used by athletes today. It has been shown to reduce estrogen levels in women with breast cancer by 98% or more (1). SO clearly, it’s useful for administration to male steroid using athletes who are eager to prevent some of estrogen’s nastier effects on their bodies- development of breast tissue, water retention, etc…
When we take a look at its effects in men, Letrozole actually reduced estrogen in one test subject to undetectable levels (2). In another clinical study, intravenous administration of Letrozole (2.5mcg for 28 days), Letrozole lowered Estrogen by 46% in the young men tested, and 62% in the elderly subjects. In addition, Letrozole also significantly increased LH levels to a whopping 339 and 323% in the young and the elderly, respectively and Testosterone by 146 and 99%, respectively. (3) Letrozole was also able to produce a peak LH response to Gonadatropin Releasing Hormone equal to a 152 and 52% increase from baseline in either young or older men, respectively.
As you can see, Letrozole is a very powerful drug, and as a result, only very tiny doses are necessary. An effective daily dose of Letrozole for most people is usually about .25-.5mg/day, even though clinically, it is typically used at 2.5mgs/day. Twenty micrograms of Letro was enough, in one study done on men, to reduce estrogen levels by almost a third. (4)
Letrozole’s effects on cholesterol are, really difficult to pin down precisely. They are, in the words of one researcher: "inconsistent.” I can tell you that in my opinion, reducing your bodies estrogen to virtually nothing, will eventually take its toll on your cholesterol profile, and will kill your sex drive and your joints- all of which require estrogen to function safely and effectively.
Even if you take very low doses of Letrozole, it will build up to reasonable blood plasma levels, as it has a 2-4 day half-life, and this long half life also means you need to take Letrozole for 60 days to get a steady blood plasma level (5), and that it will take a very long time to clear out of your system.
Letrozole is the only pharmacological “cure” for gyno that I know of to have ever worked in bodybuilders. In a study conducted on rodents, Letrozole was able to effectively destroy breast tissue tumors (6), and it’s also been effective on many bodybuilders who have used it to eliminate an existing case of gynocomastia. In my case, I used Letro to get rid of my own gyno, by starting with a dose of 2.5mgs/day and then lowering it by .25mcgs per week once my symptoms abated.
With regards to using this stuff on a cycle, unless you are extremely gyno prone, or need to reduce estrogen levels to virtually nothing (for a bodybuilding contest or whatever), it’s going to be too powerful for most people. Male and female competitors typically use it to get the last bits of estrogen related water retention out of them during the final weeks of contest preparation. But when used on a typical cycle, Letro is generally overkill unless a ripped look with zero water and estrogen is desired or if the user is prone to gyno.
Aromasin (Exemestane) is one of those weird compounds that nobody really knows what to do with. What we generally hear about it makes it very uninteresting…It’s a third generation Aromatase Inhibitor (AI) just like Arimidex (Anastrozole) and Femera (Letrozole). Both of those two drugs are very efficient at stopping the conversion of androgens into estrogen, and since we have them, why bother with Aromasin? It’s a little harder to get than the other two commonly used aromatase inhibitors, because it’s not in high demand, and there’s never been a readily apparent advantage to using it. And I mean…lets face it: It’s awkward-sounding. Aromasin doesn’t have much of a ring to it, and exemestane is even worse. Arimidex has a bunch of cool abbreviations ("A-dex" or just ‘dex) and even Letrozole is just "Letro" to most people. Where’s the cool nickname for Aromasin/exemestane? A-Sin? E-Stane? It just doesn’t work. It’s the black sheep of AIs. And why do we even need it when we have Letrozole, which is by far the most efficient AI for stopping aromatization (the process by which your body converts testosterone into estrogen)? Letro can reduce estrogen levels by 98% or greater; clinically a dose as low as 100mcgs has been shown to provide maximum aromatase inhibition (2)! So why would we need any other AIs? Well, first of all, estrogen is necessary for healthy joints (3) as well as a healthy immune system (4). So getting rid of 98% of the estrogen in your body for an extended period of time may not be the best of ideas. This may be useful on an extreme cutting cycle, leading up to a bodybuilding contest, or if you are particularly prone to gyno, but certainly can’t be used safely for extended periods of time without compromising your joints and immune system.
So that leaves us with Arimidex, which isn’t as potent as Letrozole, but at .5mgs/day will still get rid of around half (50%) of the estrogen in your body. Problem solved, right? Use Arimidex on your typical cycles, and if you are very prone to gyno or are getting ready for a contest, use Letro.