I am using phamecuetical grade gear, but my last shot on Monday is causing a lot of pain. I wasn't really thinking when I shot, but I am really careful that everthing is sterile. I used two shots the first is deca and sust. The second was winny. I shot the winny very close to the site where I shot the deca/sust. Could that be why I have the pain now? It kinda makes sense. But the shots were sperate the sites were close. Otherwise, I am at a loss. I have been using this for a while and have not had pain before.