I haven't used Reclast but my mother-in-law just got her second yearly injection. She is very frail (83 lbs) and about to turn 87. Normally she has a bad reaction to almost all medicine. She could not tolerate any of the oral medications. She tolerates the Reclast without any side effects. The doctor does bloodwork before the infusion and administers the medication through an IV about a week later. It seems to work well for her.