Does Tamoxifen build muscle, why bodybuilder use it?

We often hear bodybuilder talk about Tamoxifen, and for those who don’t know PCT, it’s a bit confusing: Does the breast cancer drug Tamoxifen build muscle, and why does bodybuilder use it?

What is Tamoxifen?

Tamoxifen, sold under the brand name Nolvadex, is FDA-approved to treat and prevent breast cancer in men and women, and it is one of the most widely used drugs for breast cancer.

The vast majority of breast cancers are hormone-dependent, with cancer cells dependent on estrogen for growth and differentiation. Tamoxifen is a selective estrogen receptor modulator that preferentially binds to estrogen receptors and prevents estrogen from binding to them. In this case, cancer cells can’t bind to estrogen and can’t grow and differentiate, which is how Tamoxifen works to prevent breast cancer.

Tamoxifen has an anti-estrogen effect in the breast, but it also has an estrogen effect, and its effect varies from tissue to tissue. In tissues such as the uterus and liver, Tamoxifen mimics the effects of estrogen and can prevent osteoporosis.

So Tamoxifen doesn’t build muscle, so why does bodybuilder use it?

Tamoxifen for bodybuilding

The antagonism of Tamoxifen against estrogen receptors prevents the negative feedback of estrogen HPGA, which increases the secretion of luteinizing hormone LH and follicle-stimulating hormone FSH, and increases testosterone production. Testosterone is a type of androgen hormone, which is effective at helping build muscle.

However, this is not why the bodybuilder uses Tamoxifen to grow muscle, which is why the bodybuilder uses Tamoxifen during the PCT cycle.

The primary purpose of PCT is to restore levels of endogenous testosterone, and it’s clear that Tamoxifen can do just that. Tamoxifen stimulates the secretion of LH and FSH, helping to restore endogenous testosterone levels as quickly as possible.

Another aim is to eliminate the effects of excess estrogen, which can be a problem with some anabolic steroids, but not all. The main side effects of estrogen are water retention and gynecomastia (gyno). Gyno is caused by the accumulation of large amounts of estrogen in the breast. Tamoxifen, as a SERM, is highly selective and prevents the accumulation of estrogen in the breast, thus effectively preventing the occurrence of gyno.

So, while Tamoxifen has the effect of boosting testosterone production, bodybuilder uses it not for muscle gain, but as an anti-estrogen and PCT drug.