Estetrol, an orally active estrogen synthesized exclusively during pregnancy by the human fetal liver, is a selective nuclear estrogen receptor modulator. Estetrol binds ERalpha as well as ERbeta (with a fourfold lower affinity). Estetrol increases eNOS expression/activity and NO synthesis in endothelial cells. Estetrol exerts estrogenic actions on the endometrium or the central nervous system but presents antagonistic effects on the breast. Estetrol can be used in contraception and menopausal hormone research[1][2][3][4].
