A Study to Evaluate the Effects of RAD1901 in the Treatment of Vasomotor Symptoms in Postmenopausal Women

Inclusion Criteria: 1. Have documented evidence of a minimum of 7 moderate to severe hot flashes per day, or 50 per week. 2. Be in good general health as determined by medical history, physical examination, and inclusion procedures and is without evidence of any clinically significant abnormalities. 3. Have a normal pelvic assessment with no clinically significant signs on examination and pelvic ultrasound. 4. Have a normal mammogram at the time of study screening. Exclusion Criteria: 1. A history of chronic or recurrent renal, hepatic, pulmonary, allergic, cardiovascular, gastrointestinal, endocrine, central nervous system, hematologic, immunologic or metabolic diseases to a degree that would compromise patient safety or interfere with the interpretation of study data. A history of active presence of thrombophlebitis, thrombosis, thromboembolic disorders. 2. A history of active presence of stroke, transient ischemic attack (TIA), heart attack or ischemic heart disease. 3. Unexplained vaginal bleeding within the 3 months prior to study entry.