Welcome to ThisIsMS. I believe that you'll find this to be a supportive community. I can't answer your questions about injection site pain with Betaseron. However, I was on Avonex for 10 years. Because Avonex is an intramuscular injection, there are very little injection site reactions. The most I got was a very rare bruise which, at its worst, was about the size of a quarter. If you're having problems with the injection site reactions with Betaseron, then you may want to talk to your doctor about possibly switching over to Avonex. The needle is larger, but once you get used to the IM injections, it's not that big of a deal.