BP Nolvadex 10 (Tamoxifen Citrate) is classed as a specific estrogen receptor modulator or SERM. It acts as an estrogen antagonist in the brain and the breast area meaning it prevents estrogen from exerting its normal effect in those areas. With respect to its action in the brain it inhibits the conversion of testosterone to estrogen which during a cycle can mean that estrogen levels remain low. Although low estrogen is often considered advantageous by bodybuilders it should be noted that estrogen helps both with the accrual of muscle mass and also helps to boost libido on cycle. In fact, when bodybuilders use testosterone enhancing compounds and run tamoxifen alongside it, they often lose out on some of the muscle gains and enhanced libido that normally accompanies testosterone elevation.
Nolvadex is typically taken at 40mg per day for the first 2 weeks of a PCT, and then reduced to 20mg daily for the final 2 weeks. Despite this, PCT is not something that is ‘one size fits all’ and Tamoxifen might not be the right choice for everyone. Newer compounds such as Raloxifene are also becoming prominent in offsetting gyno related side effects.
Although classed as an estrogen antagonist it should be noted that in some parts of the body tamoxifen actually acts as an estrogen agonist meaning it actually acts in an estrogenic manner as opposed to how most think of it being which is an anti-estrogen. When it acts in an estrogenic fashion in the liver for instance, tamoxifen can increase levels of sex hormone binding globulin (SHGB) which acts to bind to testosterone thus lowering free testosterone in the body. Free testosterone is the amount of unbound testosterone in the system and it is the level of free testosterone which is strongly correlated to the positive effects of high testosterone such as increased muscle mass, strength, and libido.