 Postmenopausal subjects with an intact uterus who meet the study entry criteria will be randomized to one of five treatment arms four active and one placebo and followed for 12 months. During the Screening period all subjects will be provided with a diary to self-assess the frequency and severity of their vasomotor symptoms. Subjects experiencing a minimum daily frequency of 7 or 50 per week moderate to severe hot flushes will participate in a VMS Substudy during the first 12 weeks of treatment. The Substudy subjects will be stratified by treatment arm within the sites, and only Substudy subjects have the possibility of being randomized to placebo. Subjects who qualify for the study except for experiencing a minimum daily frequency of 7 or 50 per week moderate to severe hot flushes will be stratified within sites to one of the four active treatment arms and followed for 12 months, but will not participate in the VMS Substudy. However, VMS information will be collected from all subjects during the first 12 weeks of treatment. All Study Subjects: Postmenopausal women with an intact uterus who seek relief from hot flushes and meet all other inclusionexclusion criteria are eligible for 12 months of study treatment. 