Tamoxiphen is a mixed agonist/antagonist.It acts as an estrogen blocker at certain sites,and behaves estrogenically in others.It also does nothing for aromitase proliferation,which means that it allows estrogen to be produced freely and circulate without disruption.This is why aromitase inhibitors such as liquidex/anastrozole are superior as estrogen combatants.They kill the problem at it's root of formation.