Testosterone is the primary substrate used in the male body for the synthesis of estrogen ,the principal female sex hormone . Although the presence of estrogen may seem unusual in men ,it is structrually very similiar to Test .With a slight alteration by the enzyme aromatase ,estrogen is produced in the male body . Aromatase takes place in various regions of the body including the liver,testes,and the central nervous sytem , in the context of the average healthy male the amount of estrogen is not very severe ,and may even be beneficial in terms of cholestrol values.
In larger amounts however it does have some rather unwanted side effects including: water retention,female breast tissue development (gynecomastia) ,and increased body fat accumulation .For these reasons many focus on minimizing the buildup of estrogen with aromatase inhibitors such as Armidex or Cytadren,or anti-estrogens such as clomid or Nolvadex , We must not however be led into thinking that estrogen serves no benefit ,as it is actually a desirable hormone in many regards .Athletes have known for years that estogenic steroids are the best mass builders ,but it is only recently that they are realizing why .The reasons go beyond simple size,weight, and strength increases that one would attritribute to estrogen-related water retention ,with this hormone actually having a direct effecton the process of anabolism,Including glucose utilization, growth hormone secretion and androgen receptor proliferation.So what does all this mean to the bodybuilder , It calls for a cautious approach to the use of estrogen maintenance drugs if mass is the goal .Obviously there is a clear need for these drugs , but if none of the related problems have presented themselves , added estrogen may indeed be helping an athlete to achieve certain goals
ref: Anabolics 2002 Teekahty fitnessgeared.com