- Women of childbearing potential (unless surgically sterilized by hysterectomy or bilateral tubal ligation, or post-menopausal for at least two years) not using a highly effective method of birth control. Highly effective methods of birth control are defined as those which result in a low failure rate (i.e., less than 1 % per year) when used consistently and correctly such as implants, injectables, combined oral contraceptives, intra-uterine devices (IUDs), sexual abstinence or a partner who has undergone a vasectomy;