Fosamax treats osteoporosis but not very well. Fosamax belongs to the bisphosphonate class of drugs along with Actonel, Boniva, and Reclast. While people generally assume Fosamax increases bone formation, actually it only modestly reduces bone breakdown without really boosting bone production.

Although bone mineral density does increase slightly with Fosamax, it relates to deposition of calcium rather than new bone formation. As a result the decrease in fractures with therapy appears much less than most people expect. Some reports suggest Fosamax only benefits those with a history of prior fracture. It may not be effective in primary prevention – preventing the first osteoporotic fracture in those at risk but without a previous incident.

Unfortunately the side effects of Fosamax may be significant and include necrosis of the jawbone and low energy fractures of the thighbone. Injury to the esophagus may occur with a small increase in the incidence of cancer of the esophagus. In most individuals Fosamax should be discontinued after 5 years. Long term therapy may be counterproductive.