The use of bone density testing to monitor the effects of treatment for osteoporosis is controversial.

Bone density testing indicates the strength of your bones and can estimate your risk of a fracture. Prescription medications such as alendronate (Fosamax) can help prevent and treat osteoporosis by improving bone strength. The U.S. Preventive Services Task Force strongly recommends initial screening for osteoporosis in women at age 65.

Although bone density testing provides information that's helpful in diagnosing osteoporosis, doubts have been raised about the accuracy of the results. Readings may vary among different testing methods and different populations.

In addition, some women appear to lose bone density during the first year of treatment with medications for osteoporosis. As a result, doctors may change treatment because a bone density measurement suggests that the medication isn't working. But a study published in 2000 found that women with the greatest loss of bone density during the first year of treatment were those most likely to gain bone density if they continued the same treatment for a second year.

For these reasons, many doctors don't retest bone density after treatment begins. The National Institutes of Health recommends continued treatment for osteoporosis regardless of the results of bone density testing or other tests for osteoporosis.