NOLVADEX GYNO :
Nolvadex is the name of the drug whose scientific name is tamoxifen citrate. Nolvadex is not a steroid - it is a potent anti-estrogen used as an ancillary drug during cycle when symptoms of gyno occur. It can also be used post cycle to restore natural testosterone production. Symptoms of gyno can occur when using a cycle which contains drugs which aromatize, including (but not limited to) testosterones such as enanthate, cypionate, and suspension.
The drug is an estrogen agonist / antagonist, which binds to estrogen receptors in different tissues. Whether nolvadex acts as an estrogen agonist or antagonist depends on which type of tissue it is working in. When the tamoxifen molecule binds to the receptors, estrogen is blocked and cannot result in any type of action - therefore an anti-estrogen effect is exhibited. Nolvadex is used clinically in the treatment of breast cancer since many forms of breast cancer are responsive to the action of estrogen. Nolvadex blocks its actions and works as an effective treatment.
Aside from direct treatment of breast cancer, it is used as a preventative measure for those with a genetic predisposition for breast cancer. While nolvadex is likely the most popular on-cycle anti-estrogen due to its affordable price, more potent remedies are avaialable such as arimidex, femara, and aromasin. These ancillary drugs prevent estrogen from being manufactured in the first place and make gyno related side effects virtually nonexistent.
There is an enzyme in the male body known as aromoatase which is capable of altering testosterone so that it forms estradiol - an estrogen derivative. Estrogen is structurally similar to testosterone and it is present in the male body, but to a much smaller extent than testosterone. Since aromatase can aromatize many anabolic-androgenic steroids, increased levels of estrogen can be a concern for the on-cycle bodybuilder. These levels can cause side effects, the main one being gyno (the development of female breast tissue in men).