Compound E (γ-Secretase-IN-1) is a potent inhibitor of γ-secretase, which blocks γ-secretase-mediated cleavage of Notch with an IC50 of 0.32 nM. It also suppresses the production of β-amyloid(40) and β-amyloid(42) with IC50 values of 0.24 nM and 0.37 nM, respectively. It also inhibits Notch signalling, significantly disrupting gonadotropin-dependent follicle growth and halting progression to the preovulatory stage of development.