The thing which, in my mind, sets it apart from other ancillary compounds currently in use today is its unique ability to inhibit the production of cortisol. Cortisol, as you recall, is a catabolic hormone, and breaks down muscle. Cytadren inhibits the conversion of cholesterol to pregnenolone (2) as well as having an aromatase inhibiting effect. Thus, Cytadren is quite unique in having both of these abilities, and certainly none of the AI´s I´ve seen thus far has anything resembling such an effect on cortisol.
Cytadren is used, medically, to fight breast cancer and/or hyperadrenocorticism, and it is the only drug currently available (to my knowledge) that can be used successfully for both purposes (1)(3). It may even have anti-depressive properties (4)(5). During a cycle, it may be used to both lower cortisol levels from intense training, and to lower estrogen levels. Sounds almost perfect, right? It´s use would allow us to consider the use of Arimidex, Nolvadex, or a similar compound for strictly post cycle use, when an increase in test, LH, and FSH would be more necessary...
Well, it´s not quite perfect, as you´ll soon see. The first problem is that it (possibly) could reduce androgen levels. The best we could hope for is that it doesn´t have much of an effect on circulating androgen levels (1).
The next problem is that eventually your body, smart cookie that it is, will start to figure out ways to compensate for the reduction in cortisol, by either producing more, or inhibiting the Cytadren´s effects. Great... And while the cortisol isn´t present in your body, your joints will be aching. Yeah, I´ve actually used this stuff (the things I do in the name of science!), and it worked& made me look a bit "dryer" and more cut; but as I recall, it also made me sleepy. This could be due to its effects on the adrenal cortex, I don´t really know, but that´s a pretty good guess.
If you are thinking about using Cytadren for this purpose, I´d have to tell you to forget it. Three grams of Vitamin C lowers your Cortisol around as much as 1,000mgs of Cytadren, from the literature I´ve seen on both, and the Vitamin C doesn´t do it at the expense of your adrenal responsiveness (7). A gram of Vitamin C lowered cortisol by 1/3rd in UltraMarathon Competitors (8) (these are the people who apparently don´t have cars, so they feel compelled to run 90 kilometers at a time). I just can´t justify taking Cytadren for an extended period of time to reduce cortisol, when Vitamin can do the same thing, more cheaply, and has other added benefits.
Next, we have to deal with Cytadren´s liver toxicity (3). This stuff is pretty stressful on your liver. I guess we can use some milk thistle and such, but do we really want to risk it, when it´s effects on cortisol are short lived and it may reduce circulating androgen levels?