Oestrogens and progesterone are two hormones responsible for female characteristics. They can be produced as a side effect of anabolic steroid use when they convert (aromatise) into these hormones. Both are responsible for some of the side effects of steroid use, eg gyno (gynecomastia - female breast tissue development in males, aka 'bitch tits'), female body fat deposition, water retention, etc.

Anti-oestrogens are compounds which act to reduce oestrogenic activity in the body. This is achieved in one of two ways, and there are different drugs which fall into these categories.

Anti-Oestrogens
Competitive Aromatase Inhibitors
Competitive aromatase inhibitors bind to the same site on the enzyme aromatase as testosterone does. This allows less testosterone to bind to aromatase, which in turn means less is converted to oestradiol (the primary type of oestrogen). An important point to note is that the amount of inhibitor required rises with increasing steroid dose i.e. higher doses of Arimidex or Proviron are required to prevent the aromatisation of 1000mg/week of testosterone than 500mgs/week.

Arimidex (Anastrozole)
Arimidex is the perfect choice for when using high doses of aromatising steroids, or indeed even for moderate doses if the individual is prone to gyno. It is thought that it may be possible to lower oestrogen levels too much with Arimidex and for this reason blood tests are recommended to determine whether the dosing schedule is correct for maximum results, as it is theorised that some oestrogen presence is required to keep the androgen receptors 'open'. Arimidex has excellent binding qualities at the receptor and therefore only low doses are required. The main downside is its price; it is very expensive (see article 'The Price of Gear')

Dosing
Arimidex is supplied in 1mg tablets.
Usual dose is between 0.25 - 1mg/day. In most cases 0.5mg/day is sufficient.

Proviron (Mesterolone)
Proviron is an anabolic steroid with little direct anabolic properties. It has good binding qualities with the androgen receptor, but most never reaches the androgen receptor in muscle tissue, as it is enzymatically converted to diol. It is however effective as an anti-aromatase, and is believed to also act in an anti-oestrogenic manner due to certain oestrogen receptor down-regulation, making it a very effective compound for preventing gyno. Proviron also helps restore sexual dysfunctions caused by steroid cycling, helping to increase sexual desire as a result of the increased androgen levels, a downside can be permanent erections in some males which at first may sound fantastic but can be extremely painful, in which case the dose should be lowered or discontinued. Proviron will also help reduce excess bloating caused by water retention.

Proviron can be used effectively throughout clomid therapy as it displays no signs of inhibiting the HPTA (see article 'Clomid and HCG'), and is helpful in keeping androgen levels elevated until natural testosterone production is restored correctly. The androgenic activity is also responsible for the distinct hardening of muscles and is one reason it is often favoured leading up to competitions.

Dosing
Proviron is supplied in 25mg tablets.
Usual dose is between 25 to 100mg/day, in most cases 25 to 50mg/day is sufficient. Dose is best split am and pm.

Oestrogen receptor antagonists
Oestrogen receptor antagonists are weak oestrogens which bind strongly to a hormone receptor, but do not activate the receptor and make it unresponsive to the stronger oestrogenic hormones present due to the aromatisation of steroids.

Nolvadex (Tamoxifen citrate)
Nolvadex is not a steroid but a triphenylethylene with potent anti-estrogenic properties. Its clinical use is primarily in chemotherapy for cancer patients. It is very useful and successful in combination with a steroid regimen at reducing water retention and preventing gyno. Nolvadex is probably the most commonly used anti-oestrogen mainly due to its mostly positive effects, availability and low price. Controversy surrounds the fact that it anecdotally appears to reduce gains made on a cycle, mostly due to reduced water retention, but most users agree that losses, if any, are minimal and its always difficult to say what gains may have been made in its absence.

Dosing
An effective dose seems to be 10 to 20mg/day.
At first signs of a possible gyno, take 20mg/day until symptoms subside, then 10mg/day until completion of cycle and post-cycle Clomid therapy.

Clomid (Clomifen)
Like Nolvadex, Clomid is not a steroid but a triphenylethylene with anti-oestrogenic properties. The two compounds are structurally similar and their mechanism of action is also similar.

The general consensus though, is that Clomid is best left as a post-cycle natural testosterone recovery product and a more appropriate anti-oestrogen found, as Clomid does not seem to be as effective in this role.

Progestins
The presence of progesterone in male bodybuilders is through the use of the progestins, i.e. Oxymetholone (Anadrol, Anapolan50), Trenbolone (Finaject, Parabolan) and Nandrolone (Deca durabolin). A large problem for the bodybuilder is that the symptoms displayed by progesterone are identical to those of oestrogen, but the concurrent use of the typical anti-oestrogens appears to have no effect in controlling or treating it.

Progesterone tends to aggravate oestrogen induced gyno symptoms, making them more difficult to cure. We will look at some methods of avoiding or controlling them, bearing in mind that progesterone actually requires oestrogen presence to activate it in the first place.

Use with non-aromatising steroids
If progesterone requires oestrogen presence to activate it, then one method of avoiding this would be to use the progestins in stacks with non-aromatising steroids. Amazingly heavy androgenic steroids like Anadrol and Trenbolone are exceptionally mild and safe with regard to female characteristics when used in conjunction with non-aromatising steroids like Primobolan or Winstrol. This is great news for the gyno-prone individual who has previously avoided these stronger steroids for fear of gyno development. A simple stack of Anadrol and Primobolan will go along way to packing on some serious mass without the worry of developing gyno.

Competitive Aromatase Inhibitors
If aromatising steroids are to be included in the stack with progestagenic steroids, then the concurrent use of Competitive Aromatase Inhibitors, like Arimidex or Proviron, would also seem a sensible option. These can be incorporated to keep oestrogen levels low and avoid the activation of the progesterone. Although they will not help with already developed progesterone induced gyno, they can certainly be employed to avoid its development. As usual, the amount of aromatase inhibitor required increases with increasing dose of aromatising steroids used, but the best dose is still the minimum amount that can be got away with to produce the desired effect.

Winstrol
The use of Winstrol is also an effective method of controlling progesterone-induced gyno, as it is anti-progestagenic. An effective dose appears to be in the vicinity of 50mg eod (depot) or 30 to 35mg/day (tabs) although this dose may require increasing depending on the doses being employed in the stack.

One important point worth mentioning is, although generally the progestins do not aromatise, there is an exception to this rule: Deca, as well as being a progestin also aromatises, only very slightly, but nevertheless, still does to some extent. Although this is not nearly enough to cause the large majority any problems at all, for those extremely sensitive to gyno, this small amount of aromatisation to oestrogen can be enough of an elevation to activate the progesterone. Very few people are likely to suffer this, but we feel it is a point worth mentioning.

All of the above mentioned compounds can be used effectively as part of steroid cycles, but careful consideration should be given to selecting the correct compound/s for the duty required.

great read!