Harvard Women's Health Watch

Do you need a drug for osteoporosis?

Several medications can maintain or increase bone density. You can choose one based on your health and preferences.

Most of what we read about hip fracture isn't good. It is a major cause of disability, nursing home admissions, and death in older women. But there is a promising trend: hip fractures in the United States have been on the decline since 1996. Although better nutrition, increased physical activity, and education on fall prevention may have played a role, the drop in fractures has also coincided with the widespread availability of bisphosphonates—a class of drugs first approved in 1995 to increase bone density.

Dr. David Slovik, an endocrinologist at Harvard-affiliated Massachusetts General Hospital, says, "That reduction is likely due in large part to the use of bisphosphonates, along with our ability to diagnose and treat osteoporosis earlier. These medications play an important role in building bone strength and preventing fractures."

The drugs are designed to treat bone loss rather than prevent it. They are often prescribed after a test called dual energy x-ray absorptiometry (DEXA) indicates that a person has low bone density and thus an increased risk of fractures. The test result, expressed as a number called a T-score, is a comparison of your bone density to that of a healthy 30-year-old woman. Drugs are generally recommended for women who meet any of the following criteria:

  • T-score of –2.5 or lower—the threshold for diagnosing osteoporosis
  • a hip or vertebral fracture caused by a fall from standing (in contrast to a fall from a height)
  • T-score between –1.0 and –2.5 and a high risk of osteoporosis-related fracture in the next 10 years.

How the drugs work

Bone is a living tissue that is continually breaking down and reforming—a process called bone remodeling. Bisphosphonates interfere with bone breakdown, as does denosumab (Prolia)—a monoclonal antibody that blocks osteoclasts, the cells that break down bone. Estrogen products (Premarin and many others)—which are taken primarily to relieve menopause symptoms­—and raloxifene (Evista), a selective estrogen-receptor modulator (SERM) also block remodeling, but to a lesser extent. Another drug, teriparatide (Forteo), builds bone by stimulating the development of osteoblasts, the cells that orchestrate bone formation.

Which drug is best for you?

Bisphosphonates are fairly effective, generally safe, and are still first-line therapy. If you have difficulty taking an oral bisphosphonate­—or can't take one for any other reason­—an injectable drug might be a good alternative. You and your clinician can consider your health, ease of use, and side effects in weighing the alternatives.

Medications that can maintain or increase bone density

Generic name

Brand name

Type and use of medication

Side effects/comments




Daily tablet or weekly liquid or tablet

Oral bisphosphonates may cause heartburn, or irritate the esophagus if not taken properly. Injections and infusions may cause flu-like symptoms. Risk of jaw necrosis and thigh fractures is less than 1%.



Daily or monthly tablet, or quarterly intravenous injection



Daily, weekly, or monthly tablet

zoledronic acid


Infusion­—annually for treatment, biennially for prevention

Monoclonal antibody



Injection every six months

Long-term safety not yet established.

Hormone therapy


Premarin, others

Tablets and patches

Increased risk of stroke, uterine cancer.

estrogen and progestin

Prempro, others

Tablets and patches

Increased risk of breast cancer, stroke, heart attack.

Selective estrogen-receptor modulator, or SERM




May cause hot flashes.

Synthetic parathyroid hormone, or PTH



Daily injection

Little long-term safety data, so limit use to two years.

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