I was on Chantix twice, last time was for 3 months and just ended it on 8/11. First time I quit for 1 yr. and had a dumbass attack and started again, smoked for 3 months and went back on chantix, not smoked for 1 1/2 months now. It's still a daily struggle, but it passes. I did have some nausea, only because I didn't eat before taking it. I would suggest you eat alot before you take it. Good Luck to all, just remember, you didn't start smoking overnight, don't think you can quit overnight. ( i smoked for 31 years, and i'm 43 years old, it was a way of life not just a bad habit)