Tamoxifen (Tamoximed, Nolvadex)

Description

TAMOXIFEN (NOLVADEX) FOR BODYBUILDING USE

We get an almost daily question where customers ask us what we suggest for PCT, and how the person in question has been told by everybody they must use a prescription breast cancer drug called Tamoxifen (sometimes sold under the brand name Nolvadex), to ensure they retain their muscle gains and prevent potential problems with gynecomastia. This article will go into some of the details on why Tamoxifen has been recommended for bodybuilders, as well as some side effects that most people fail to understand before embarking on the use of this compound.
What Does Tamoxifen Do?

Tamoxifen 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.
Tamoxifen dosage used in bodybuilding

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.
Negatives Of Tamoxifen Use

tamoxifen

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.

By lowering free testosterone, tamoxifen has the potential to hurt our bodybuilding gains. This helps to explain why we never hear of people using tamoxifen on a standalone basis (similar to how a testosterone booster is used) and gaining any muscle mass despite the significant rise in testosterone it is capable of producing. Quite simply, a lot of the testosterone rise is cancelled out by the increase in SHGB. Another negative of tamoxifen’s action in the liver is its ability to suppress production of the peptide hormone IGF-1. IGF-1 is broken down from growth hormone and is considered to be more potent than growth hormone itself for the purposes of building muscle tissue. High IGF-1 levels make a big contribution to the process of building a better physique and the ability of tamoxifen to suppress IGF-1 levels is another reason why tamoxifen use tends to be disappointing for the purposes of building muscle mass.

In fact, a recent study which showed a rise in total testosterone (they failed to measure free testosterone or levels of SHGB) and a reduction in IGF-1 levels after tamoxifen usage is a significant indicator as to why it can prove disappointing for the building or maintenance of muscle mass.(1,2) The fact that tamoxifen is referred to as an anti-estrogen overlooks the fact that outside of certain tissues it promotes estrogenic effects. A study published in the Journal of Endocrinology(3) showed that long term tamoxifen use increased serum testosterone levels by 50% which is certainly a healthy increase. However, at the same time serum estrogen levels increased by a massive 341%. In fact, in the control group in this study, which only used tamoxifen for a week, estrogen rose after just four days. Considering that the subjects in this trial used tamoxifen at a lower dose of just 10mg it begs the question of what would happen if used at the higher dosage typically seen in bodybuilding circles.
Tamoxifen and gyno in bodybuilders

Tamoxifen is of course frequently used to suppress estrogenic action in breast tissue to prevent gynecomastia for which it can work rather well during cycle. It will not totally eliminate the possibility of gyno though especially with those steroids that act in a progesterogenic fashion for which something that lowers prolactin such as the supplement Vitex will be required. Assuming though that your cycle went well and you ran a PCT and you battled through the suppressed sex drive, low IGF-1 levels and low free testosterone levels seen with tamoxifen usage. What happens when you remove tamoxifen? If we consider the study above which shows a profound rise in estrogen in the body during tamoxifen use, its removal is going to create a situation where we now have high estrogen levels in the body and with nothing to stop this estrogen from causing gyno in male bodybuilders. This creates a recipe for the kind of rebound gyno that you often hear people complaining about on bodybuilding forums. Adding insult to injury, high estrogen levels are suppressive in their own right which can cause delayed progress in the gym when coming off tamoxifen use