5 Medications Can Thin Bones and Raise Fracture Risk, Experts Say
Bone health specialists say commonly prescribed drugs, from steroids to breast cancer treatments, can lower bone density and make fractures more likely. They explain who is at risk, how long exposure matters and what patients can do to protect their bones.
Experts say 5 medications can cause bone thinning and raise the risk of fractures, even when patients take them for unrelated conditions. Specialists in bone health detailed the risks in guidance published November 9, 2026.
The drugs treat everything from asthma attacks to breast and prostate cancer. Knowing the risk lets patients work with their doctors on a plan to prevent or limit the damage.
"Knowledge is power," said Natasha Trentacosta, a board-certified orthopedic surgeon at Cedars-Sinai in Los Angeles. "When we understand the skeletal consequences of a necessary medication, we can take meaningful steps to protect bone health while continuing potentially lifesaving therapy."
Bones naturally lose density with age and after menopause. A lack of weight-bearing exercise or resistance training also contributes.
Corticosteroids
Corticosteroids such as prednisone reduce inflammation by tamping down the immune response. Doctors prescribe them for lupus and other autoimmune diseases, asthma, rashes, severe allergies and conditions such as tendinitis.
They increase the activity of osteoclasts, the cells that chew up bone, and can interfere with calcium absorption, said Naim Maalouf, associate director of the Center for Mineral Metabolism and Clinical Research at the University of Texas Southwestern Medical Center.
Trentacosta said the drugs also suppress osteoblasts, the cells that build new bone. They can shorten the survival of both osteoblasts and osteocytes. The result, she said, is a significant drop in bone formation and in the bone's ability to repair itself.
The effects are so well documented that the condition has a name: steroid-induced osteoporosis.
Duration matters. A single course of a week or two is generally not a major concern, Maalouf said. It may alter bone cells briefly but should not cause lasting thinning.
Higher daily doses and repeated, prolonged exposure raise the risk of fractures, Trentacosta said. Inhaled steroids, such as those for chronic respiratory illness, may have a small effect depending on dose, frequency and other risk factors.
The American College of Rheumatology recommends a fracture risk assessment for anyone taking at least 2.5 mg of prednisone, or an equivalent drug, daily for more than three months, Trentacosta said.
For patients at elevated risk, bone-protecting medication may need to start alongside steroid treatment. Doctors should not wait for a fracture or markedly abnormal bone density results, she said. Options include bisphosphonates, denosumab and parathyroid hormone analogs, depending on fracture risk, other conditions and other medications.
Aromatase inhibitors
Aromatase inhibitors, including anastrozole, letrozole and exemestane, treat estrogen receptor-positive breast cancer. They are known to cause bone density loss and increase fracture risk.
Patients usually take them for about 5 to 10 years, depending on the cancer and the person. The drugs block an enzyme needed to produce estrogen.
When estrogen levels fall dramatically, the body breaks down bone faster than it can rebuild it, Trentacosta said.
