Actonel (generic: risedronate) is a prescription medication used to treat conditions in which bones become weak and break easily such as osteoporosis and Paget's disease.

Actonel belongs to a group of drugs called bisphosphonates that work by preventing bone breakdown and increasing bone density. 

The medication comes in the form of a tablet and a delayed-release tablet. Depending on which form you take as well as other factors, Actonel is taken daily, weekly, or monthly.

Common side effects of Actonel include back and joint pain, stomach area (abdominal) pain, and heartburn. Actonel can cause esophagus (tube connecting the throat to the stomach) problems and low calcium levels in your blood (hypocalcemia).