Hi there...I have been taking Avonex for just over a year. At first I wasn't sure I'd make it on it but now it's no problem at all. I think it took 2 - 3 months before I wasn't really tired and sore for a day or so after I did the injection. Now, I barely even seem to have pain. I am still tired, not the day after, but the day after that. It's a weird delay that happens every time. I still have to be sure that I take my Advil before the shot or I am sore and get the chills. A few Advil before-hand does the trick though. Good luck with it! It will get better.