It's not bad at all. It's a pretty sharp pinch when they inject and it burns a bit as they put it in, but I personally think that getting a shot in the mouth for dental work is worse....as far as the injection goes. The soreness afterwards isn't that bad. It's like a very localized, overworked muscle...except that you may have a knot until the meds work their way into your body. It can be tender if you sit wrong or bump something. It's one of the few shots you should probably rub so that they meds are absorbed faster.