To compare the effects of 2 years of lasofoxifene treatment with 2 years of raloxifene 60 mg/day use and 2 years of placebo use on bone mineral density (BMD) of the lumbar spine.

Inclusion Criteria:

• Postmenopausal women with low bone density (osteopenia) and screening labs, pelvic ultrasound, mammogram without significant findings

Exclusion Criteria:

• Presence of metabolic bone disease, fractures, blood clots, or recent cancer.
• Any use of selective estrogen receptor modulators, investigational drugs, or recent use of osteoporosis treatments, certain hormones, or medication for blood clots or seizures.