Newbie here!
According to the drug insert side affects are: nausea( I do get nauseous about 20 min after I take it if I do not take it with food, so take with food!), headache (Ihave not had headaches, gas (I have not had gas), and a change in dreams with very vivid/surreal dreams being very common (this I have, the dreams are sometimes so real, I really have to think about if it really happened or not, but no nightmares, just dreams about everyday things). Chantix really works for me, you have no physical withdrawal, you know how when you go without a cigarette for an hour or 2 and it feels as if every fiber in your body is screaming for one? That does not happen with chantix, it binds to the same receptors as nicotine, giving the nicotine nowhere to go and your nerves thinks it is getting nicotine so you aren't craving it, and also chantix releases a small amount of dopamine, the same brain hormone released when you smoke, dopamine actives the pleasure centers of the brain, that's why alot of people feel like smoking helps them to calm down, because it does. Like I said, it has worked for me, and several people I work with, so talk to your dr about it. It is fairly new to the market, just released in July/August...you can also look it up on the net. Good luck!!!