I've been taking Zyban since Friday and have noticed a great side effect of taking them!
I have had bad back and shoulder pain for about ten years and had always put it down to the effect of having a rather large chest resulting in poor posture etc. On Saturday I suddenly realised that I had no pain!
I'm not sure if there is something in the Zyban which is blocking the pain or if it is the fact that I'm feeling soooooooo relaxed. I'm hoping that it's because I'm feeling relaxed which would mean that all of pain is muscle/tension related and I just need to work on relaxation techniques when I stop the Zyban.
I'm going to mention it to my doctor when I see him next and see what he says. I haven't been pain free for years...it's really amazing!