Category: pharmacological
Aliases: Nolvadex, ICI 46474
Triphenylethylene SERM. Tissue-selective ER agonism/antagonism: antagonist in breast (anti-proliferative, primary indication), partial agonist in bone (protective) + endometrium (hyperplasia / cancer risk) + liver (lipid + clotting-factor effects). Activity driven primarily by the CYP2D6-derived metabolite endoxifen (~100× ER affinity vs parent). In men: blocks hypothalamic ER-mediated negative feedback → raises LH/FSH → testicular testosterone — rationale for PCT after AAS cycles and off-label treatment of gynaecomastia.
PO: 96h