(E/Z) -Droloxifene

(E/Z) -Droloxifene is a mixture of its geometric isomers. The (E) -isomer is a potent selective estrogen receptor modulator (SERM) with demonstrated in vitro anti-proliferative activity in estrogen-responsive breast cancer cell lines (e.g., MCF-7) and in vivo uterotrophic effects in rodent models, while the (Z) -isomer is largely inactive.