I took Arimidex for 12 years. Yes, 12 years! It caused osteoporosis, and eventually I had three exercise-related fractures. It also caused me to feel "creaky," like I was the Tin Man in the Wizard of Oz. HOWEVER....I'm now 13+ years out from my diagnosis and I will say, in hindsight, it gave me peace of mind that I was doing all I could to prevent a recurrence. That's not nothing.