Fulvestrant (Standard) is the analytical standard of Fulvestrant. This product is intended for research and analytical applications. Fulvestrant (ICI 182780) is a pure antiestrogen and a potent estrogen receptor (ER) antagonist with an IC50 of 9.4 nM. Fulvestrant is also a GPR30 agonist. Fulvestrant effectively inhibits the growth of ER-positive MCF-7 cells with an IC50 of 0.29 nM. Fulvestrant also induces autophagy and has antitumor efficacy[1].