Tamoxifen (Nolvadex)

Tamoxifen, known as Nolvadex, is a selective estrogen receptor modulator (SERM). In medicine it is best known from breast cancer therapy. In the performance corner it is used for PCT and especially against gynecomastia.

The difference from aromatase inhibitors: Tamoxifen does not lower the estrogen level but blocks the estrogen effect where it causes trouble, mainly at breast tissue.

Tamoxifen acts differently depending on the tissue. At breast tissue it blocks the estrogen receptor, which is exactly what stops or slows the formation of breast gland tissue (gyno). At the hypothalamus it acts similarly to Clomifene and drives the body's own testosterone production via more LH and FSH.

So Tamoxifen covers two uses: gyno control and PCT support.

Oral, once daily.

• One dose per day is enough given the long half-life.
• With some water, with or without food.
• For acute gyno it is dosed higher and shorter, for PCT lower over several weeks.

A controlled study (Boccardo, 2005) examined the prevention of gynecomastia under an estrogen-driving therapy. Result: in the placebo group 73 percent developed gyno, with Tamoxifen 20mg only 10 percent. The aromatase inhibitor anastrozole was clearly weaker in this study (51 percent).

That is a strong argument for why Tamoxifen is the first choice for acute gyno and not an aromatase inhibitor.

• Possible negative shift in blood lipids and IGF-1 values.
• Gastrointestinal complaints, rarely visual disturbances.
• Very rarely an increased thrombosis risk, especially with pre-existing risk.

• At the first signs of gyno (lump, tenderness behind the nipple) Tamoxifen is the standard.
• 20mg is usually enough, higher only briefly for acute gyno.
• Banned in official competition (WADA S4).

Store dry, cool and protected from light, out of reach of children. Keep the original container closed and mind the expiry date.