The purpose of this study is to compare treatment with both teriparatide and raloxifene with teriparatide alone. The study will evaluate any side effects that may be associated with the two drugs and may help to determine whether teriparatide and raloxifene together can help patients with osteoporosis more than teriparatide alone.

Inclusion Criteria

• Must be diagnosed with osteoporosis.
• Must be female, age 45 through 85.
• Must be at least 5 years postmenopausal.
• Must be free of other severe or chronically disabling conditions.
• Must be able to properly use injection device.

Exclusion Criteria

• Must not have bone diseases other than osteoporosis.
• Must not have history of certain cancers.
• Must not have certain medical diseases (inflammatory bowel disease, malabsorption syndrome, kidney or bladder stones, venous thrombi or emboli, recent vaginal bleeding due to unknown causes).
• Must not have taken or are currently taking certain types of medicines.
• Must not have known allergy to the study agent or SERM.