Ormeloxifene does not affect ovulation. It has been shown to increase the rate of blastocyst development and to increase the speed at which the blastocyst is moved from the fallopian tubes into the uterus. Ormeloxifene also suppresses proliferation and decidualization of the endometrium (the transformation of the endometrium in preparation for possible implantation of an embryo). While they are believed to prevent implantation rather than fertilization, exactly how these effects operate to prevent pregnancy is not understood
