Hi Joanne -
I have been on the Chantix almost 2 months. I get a little nausea, but not if I take it right after I eat. I would say the worst side effect for me has been the constipation and I have become a little more tired than usual..I too am a migraine sufferer, and I wll say (knock on wood) that since I stopped smoking, I have had NONE. I am starting to think the cigs were what was causing my headaches. I have quit on the lozenges, patch, Zyban, and the Chantix is hands down the best one. Good luck to you!!