I have also had reactions since day 1. Muscle/nerve pain in my back. I did have 4 compression fractures in my thoracic spine before starting medication and I was diagnosed with osteoarthritis as well so hard to tell where the pain is from, but the timing was suspicious. My pain kept increasing and by shot #11 I had enough so I opted out of the last shot. Getting my dexa this week and then deciding where to go from here, either Fosamax or Reclast. Side effects from both scare me but I'll have to choose something. Hoping at some point to go back to Forteo which I had no problems with but my dr stopped me after 8 months because of elevated alkaline phosphotase levels. Good luck to you!