A Phase 3, Randomized, Three-Cycle, Double-Blind, Placebo-Controlled Study to Evaluate Induction of Secretory Conversion of Endometrium and Withdrawal Bleeding for Secondary Amenorrhea

Inclusion Criteria: * Be female, premenopausal, 18 to 40 years of age (inclusive, at the time of randomization) * Have secondary amenorrhea, defined as the absence of menstruation for at least 90 days prior to Visit 1 (Cycle 1, Day 1). * Have an intact uterus. * Be otherwise healthy, as judged by the Investigator physician, based on a medical evaluation performed during the screening period prior to the initial dose of Estrace®. The medical evaluation must include: * a normal or non-clinically significant physical examination, including vital signs (sitting blood pressure, heart rate, respiratory rate and temperature). Acceptable sitting systolic blood pressure is \<140 mmHg and diastolic blood pressure is \<90 mmHg at screening. A subject may be taking up to two antihypertensive medications. * a normal or non-clinically significant pelvic examination performed during screening. * a normal or non-clinically significant clinical breast examination performed during screening. An acceptable breast examination is defined as no masses, adenopathy, or other findings identified that are suspicious of malignancy. * a normal or non-clinically significant 12-lead ECG as determined by the Principal Investigator (PI) or medical Sub-Investigator. * Have a negative serum pregnancy test at Screening, and be willing to use an acceptable form of non-hormonal birth control (e.g., barrier method with spermicide) during the study. (The "rhythm method," withdrawal, or an IUD are NOT acc…