When I started the chantix i got a bit of nausea the first day. I cut the dose from 1mg to ,05mg and the worked. As my body got used to it (about 3 days) I went back to the 1mg and have been on for 2 months now. I am still smoking but maybe 2-3 cigarettes day. The chantix is slowly taking away the desire. I used to smoke a stogy every hour and now I go hours w/out thinking about it so it seems to be working for me. I also take 20 mg of methadone and it d/n interfere w/that. The onle side effects are an insatiable thirst and very vivd dreams-not scary, just very detailed and I actually remember them where I rarely did. I plan to follow through the 3 month program because it seems to be working for me.