In 2011, the agency voiced concerns that taking the drugs long-term may actually make bones weaker and increase the risk of rare but serious
side effects such as atypical fractures
of the thigh bone, esophageal cancer and
osteonecrosis of the jaw, a rare but painful condition in which the jaw bone crumbles. To investigate, the FDA reviewed data from women who had taken the drugs for six to 10 years.