Arimidex is an anti-estrogen Aromatase Inhibitor (AI) drug which was originally formulated as a medication for breast cancer in post-menopausal women and is still used for that purpose today.
It’s generic name is Anastrozole and while there are several other brand names used around the world, Arimidex is by far the most common and widely used and known, and it’s the Arimidex brand that is very popular among anabolic steroid users to address the estrogenic side effects we experience with the use of many anabolic steroids. For this purpose, Arimidex is almost always recommended for use in a steroid cycle.
My Arimidex guide has been broken down into the following sections:
Table of Contents
What is Arimidex (Anastrozole)?
By blocking the aromatase enzyme, Arimidex directly lowers the levels of estrogen circulating in the body. This is critical for treating breast cancer because of estrogen’s function on cancer cells, but also serves a great purpose for users of anabolic steroids as estrogen is the enemy of steroid use and is responsible for many of the severe side effects we all want to avoid.
As an aromatase inhibitor, Arimidex is considered the most effective choice for combating the estrogenic side effects of aromatizing steroid use like gynecomastia, water retention and the associated high blood pressure that can come with excess water retention.
While not all steroids aromatize, the most common anabolic steroids that you’re likely to be using, like all forms of testosterone, Nandrolone, Dianabol and others come with strong estrogenic effects as a result of aromatization and therefore the use Arimidex is going to be a high priority for the majority of steroid users, whether you’re a beginner or advanced user or somewhere in between.
Editor’s Note: For real, NO-BS information on cycling steroids (full suggested dosages, recommended anti-estrogens, and post-cycle therapy) be sure to check out Straight From the Underground (my recommended underground steroid handbook). Everything in this book is based on first hand experience, not theory.
Arimidex for Gynecomastia and Estrogen Control On-Cycle
Using Arimidex during a steroid cycle is almost universal among steroid users as a estrogenic related side effects protection strategy. The main estrogenic side effects of aromatizing steroids are water retention (and possible high blood pressure), and gynecomastia. Arimidex is considered as extremely effective at inhibiting the aromatase enzyme which brings about these side effects in steroid users.
Because Arimidex stops the rise of estrogen levels at the most basic level, rather than selectively blocking some receptors like SERMs do, most bodybuilders prefer Arimidex for its more powerful estrogen controlling ability and many no longer use SERMs, while some steroid users will use a combination of both SERMs and AIs like Arimidex.
As a bodybuilder using steroids, the two side effects you always want to avoid are water retention and gyno. These are both caused by rising levels of estrogen as your natural testosterone is suppressed while taking steroids.
The more powerfully aromatizing the steroid or steroids you’re taking are, the more severe your estrogen related side effects will be when it comes to gyno and water retention. The initial symptoms of gyno include tenderness and swelling of the breast tissue, and this is an initial sign that gyno is taking hold as a result of your steroid cycle.
While advanced steroid users will know how to prevent this occurring through the proper use of Arimidex and other drugs, new steroid users can take some time to balance the right dosage of steroids with that of Arimidex, but it’s critically important that the symptoms of gyno are not left to progress to a stage where they are not reversible through any means besides invasive surgery. Arimidex makes it possible to avoid getting yourself into that situation, and therefore should be considered as just as an important part of your steroid cycle as the steroids themselves are.
Water retention is the other area where we need to be focused on estrogen control during a steroid cycle. Bloating caused by water retention is not only unsightly for your physique, but can give you a false sense of achievement with your gains, which quickly turns to disappointment once you realize the weight gained was mostly water rather than muscle. But even more serious is the issue of high blood pressure that can result from excess water retention – increasing the risk of stroke or heart attack.
It goes without saying then that controlling water retention as much as possible is vital not only for your results, but your health too. Arimidex with its anti-estrogen functionality provides an important tool for steroid using bodybuilders to prevent or at least greatly minimize water retention during a steroid cycle.
Arimidex for Post Cycle Therapy (PCT)
Arimidex has the ability to stimulate natural testosterone production in men and this can make it useful during post cycle therapy where the goal is to build up natural testosterone levels again after they’ve been strongly suppressed during an anabolic steroid cycle. But for most guys, Arimidex alone will not be strong enough as a testosterone stimulator to use alone in PCT, and some choose not to use it at all.
The main reason for not including Arimidex in PCT is because of its very powerful estrogen lowering effect which in some cases can cause levels of the hormone to drop too low to support proper body functioning – so while estrogen is not a prime hormone for males, some is still required and the use of Arimidex during PCT can inhibit this necessary function and therefore not provide the beneficial effects you really need during PCT.
This can come as some surprise to new anabolic steroid users who assume AIs, with their exceptionally powerful estrogen reduction ability, must be the best option for PCT as well but most users will choose to go the route of SERMs like Nolvadex, Clomid and combine these with hCG for maximum effect during PCT, where your core goals are stimulating natural testosterone function again and avoiding the horrendous symptoms of low testosterone, plus ensuring all or most of the gains made during your steroid cycle are maintained.
When it comes to these PCT goals, Arimidex is rarely the most ideal drug to include in the cycle despite its excellent and important usage during your steroid cycle itself.
Arimidex Dosage During Anabolic Steroid Use
Arimidex is highly effective at low doses for estrogen control when using steroids that aromatize. Many guys will find that 0.5mg every two days is enough to mitigate all side effects. Others will need to increase to 1mg every two days. While some people will take as much as 1mg of Arimidex everyday during a cycle this is usually unnecessary and it’s also advised to test your individual response to the drug by starting out at the lower dose.
Female Arimidex Dosage
Because it has such strong estrogen suppressive effects, Arimidex is mostly only given to post-menopausal women as a breast cancer treatment to slow the growth of some types of tumors and where the cancer is still progressing after the use of SERM drugs. The most common dosage is 1mg daily.
Many women will be required to take Arimidex for up to five years to help control the growth of cancerous tumors. This long term administration of Arimidex comes with increased risk of side effects that we rarely or never see with the short term use that anabolic steroid users undertake with this drug.
As Arimidex is not prescribed medically for the majority of women with breast cancer who have not yet reached menopause, female anabolic steroid users also should not use this drug for any purpose.
Arimidex Dosage for PCT and Increased Endogenous Testosterone Secretion
As mentioned already, Arimidex is not a prime choice for post cycle therapy purposes for the majority of anabolic steroid users.
While it has some function for helping stimulate the production of testosterone, its highly suppressive effects on estrogen can result in a less than ideal effect on testosterone production and a result that is not as effective as using SERMs like Nolvadex and Clomid, which are more commonly used for PCT purposes, in conjunction with hCG (Human chorionic gonadotropin).
While everyone reacts differently to different drugs, and your PCT will also depend on the type of steroid cycle you were on, some may wish to include Arimidex and in these cases a dosage of 0.5mg to 1mg daily during the PCT cycle is sufficient.
Arimidex vs Nolvadex for PCT
More and more bodybuilders are turning to AIs like Arimidex to meet their needs for a powerful and effective anti-estrogen while using steroids because AIs actually block the function of estrogen, while SERMs like Nolvadex are very selective in how and where they can stop the functioning of estrogen. But many of us are still using Nolvadex and other SERM’s, often in conjunction with AIs.
How does Nolvadex compare with Arimidex and should you still be using a SERM at all? It’s not so black and white, and ultimately it comes down to how your body reacts to the drugs and the strength of your steroid cycle and the associated side effects.
A big advantage that Nolvadex and other SERMs have over Arimidex and AIs is that while Arimidex is likely to have a negative impact on your cholesterol by lowering HDL cholesterol – the good cholesterol type and this is amplified further when it’s used with most anabolic steroids, Nolvadex does not come with this concern.
In fact Nolvadex can potentially be good for cholesterol; quite the opposite to Arimidex in this regard. This is a big reason, especially for those concerned with cholesterol health, that people will choose to use SERMs over an AI like Arimidex particularly for more mild steroid cycles where an AI might not be needed anyway.
There’s another huge benefit to Nolvadex though: it is very effective during post cycle therapy to stimulate the natural production of testosterone following suppression during a steroid cycle.
Arimidex and SERMs in general simply don’t excel at this function because although it has some testosterone stimulating effects, the way Arimidex suppresses estrogen so much that there is not enough for normal functioning makes testosterone stimulation quite weak and not often enough to provide the much needed benefits during PCT.
Therefore Arimidex is rarely recommended for use during PCT and instead is considered to be a drug that is mostly used during a steroid cycle which is where it’s performance and results does outshine that of Nolvadex. That’s not to say that bodybuilders don’t use Arimidex during PCT: many do but only in conjunction with other drugs so that every possible angle is covered to aid in total recovery from a powerful steroid cycle.
For people foregoing Arimidex altogether during PCT, a combination of Clomid, Nolvadex and hCG are often used instead. The ultimate goal of PCT is to stimulate testosterone not only for normal functioning as a male, but also to retain your muscle gains and control body fat – both of which will suffer when testosterone levels are lower than normal.
Arimidex Side Effects
As a drug designed for women, most of the side effects listed and known about relate to Arimidex’s impact on the female body and in particular how the substantial reduction of estrogen brings about most of these side effects.
Since estrogen is the primary female sex hormone, it is clearly going to have a heavy impact on female when Arimidex reduces estrogen to the levels that it does – while when men use Arimidex this estrogen reduction is welcomed rather than a hindrance in most cases. Additionally, as a breast cancer treatment Arimidex is almost always taken over very long periods of time compared to the length of time it’s used for by steroid users.
But all of this doesn’t mean there aren’t side effect risks for anabolic steroid users who take Arimidex, but they are not going to be as extensive or severe. One of the main concerns surrounds a possible reduction in bone mineral content (BMC) which can lead to a higher risk of fractures and bone weakness, especially among people who lift heavy weights.
While most steroid users are unlikely to see a noticeable issue with bone mineral content reduction with Arimidex, some bone or joint pain can occur but usually subsides once you stop the drug. Since many steroids actually improve BMC, this side effect is even less of a concern for steroid users.
The second most concerning side effect of Arimidex revolves around cholesterol. When this drug is used with many types of anabolic steroids which themselves are known to have a bad effect on HDL cholesterol levels by lowering them (and sometimes significantly), Arimidex can make this worse.
While a reduction in HDL is almost always reversible after stopping steroids, it’s still critically important to follow a diet that is low in saturated fat and higher in cholesterol friendly foods like those rich in omega-3 fatty acids.
Cardio work is also advised so you can keep cholesterol levels as optimal as possible during this time. If you are prone to high cholesterol then choosing a SERM for on-cycle estrogen control rather than an AI like Arimidex can eliminate this problem for you.
Other uncommon possible side effects of Arimidex include fatigue, headache, nausea and hot flashes but once again these are almost always only seen in women who use Arimidex for long periods of time.
What is the purpose of Arimidex?
The original purpose of Arimidex is to treat breast cancer in post-menopausal women where the cancer is being promoted by estrogen, where Arimidex is able to minimize the amount of estrogen in the body and slow or stop the growth of breast cancers.
This estrogen lowering function of Arimidex is highly desirable to anabolic steroid users as well, with excess estrogen being a side effect of steroids that have aromatization properties – causing unwanted side effects like breast growth (gyno) and water retention. The purpose of Arimidex for steroid users then is to reduce estrogen while on steroids so these side effects don’t occur or are minimized as much as possible.
Is Arimidex an estrogen blocker?
Arimidex blocks the aromatase enzyme which is a critical part of the estrogen biosynthesis process – without this enzyme, production of estrogen can be stopped. Compare this to SERMs which block estrogen receptors selectively. Both can be considered estrogen blocks in some regards, but Arimidex and other aromatase inhibitors do so on a much more systemic level compared with SERM drugs which only affect particular parts of the body that they are targeted to.
Can Arimidex cause weight gain?
Weight gain is not known to be a side effect of Arimidex either for women using it for breast cancer or men using it for estrogen control when using steroids. Any weight gain during cancer treatment under Arimidex is not thought to be directly caused by the drug itself.
Can Arimidex cause hair loss?
The estrogen lowering effects of Arimidex and other hormone treatments taken during breast cancer treatment can potentially cause hair thinning in women. But this is not a known side effect for male anabolic steroid users who use Arimidex. A much bigger concern is the side effect of many anabolic steroids of hair loss or male pattern baldness.
Does Anastrozole lower testosterone?
Arimidex does not lower testosterone, but instead is known to potentially increase testosterone levels while lowering estrogen levels. This is why the drug is sometimes used to treat low testosterone in men in place of hormone replacement therapy, usually where lowered testosterone is caused by aging.
Studies have shown that rather than decreasing testosterone, Anastrozole effectively increases the available serum testosterone in elderly men with mild hypogonadism, with results showing the testosterone levels can return to normal range, while at the same time slightly reduced while staying within normal range for males.
Does Arimidex raise testosterone?
Arimidex is sometimes used as an alternative remedy to testosterone replacement therapy in men with low testosterone. Studies have shown though that it’s still not certain whether aromatase inhibitors are really effective at stimulating testosterone to a high enough level in low testosterone men; and when using anabolic steroids your body will be in a low testosterone state.
So while Arimidex does have some testosterone stimulating ability, it is not considered to be strong enough to combat very low testosterone which is why it’s not often included in PCT cycles.
How quickly does Arimidex lower estrogen?
Arimidex starts working quickly and has a half life of between 30 and 60 hours. Despite this it can take some time for concentration of the drug to build up in the blood plasma to reach the peak level, and this can take about a week.
Despite this, impressive amounts of estrogen reduction have been noted in studies on the use of Arimidex in women at the medical dosage of 1mg daily, with a 70% reduction within just 24 hours, and after 14 days estrogen had lowered by 80%. Circulating estrogen levels remained this low for up to 6 days after the last dosage of Arimidex.
How much does Arimidex cost?
Where you live will greatly determine the costing of Arimidex. For example in countries like Australia where pharmaceutical drugs are subsidized, 3 boxes of 30 tablets of Arimidex 1mg costs $20 or less. In the USA the same product can cost over $1400 when buying with a prescription.
Most steroid users won’t have a prescription for Arimidex and will get them through other suppliers or research labs. Buying on the black market is not legal in the US, while it is legal to purchase from research labs only if used for research purposes – so like all drugs we acquire for bodybuilding use, caution should be taken when it comes to legalities.
Can Anastrozole cause liver damage?
People with existing liver problems might see a worsening of the condition when using Anastrozole due to inflammation. This is mostly a concern when women are using the drug long term for cancer treatment; often over a period of years.
Medical information about Anastrozole indicate that the drug can cause liver damage, and this can be considered the case with almost any type of oral medication. Anyone using Arimidex who is concerned about its impact on the liver can have liver function tests done by your doctor and to watch for signs of jaundice or darkened urine which can indicate liver toxicity.
My Conclusion and Recommendation
As an anti-estrogen, Arimidex is used to reduce the estrogenic side effects of steroid use like gyno, water retention and reduced testosterone production. Arimidex works to lower estrogen by blocking the aromatase enzyme that converts testosterone to estrogen.