I took it for 2 weeks less than 3 months.
My wife and I had flown to LA on our Honeymoon and I missed like 2 doses so I just said fuck it I don't need this anymore.
In hindsight - I still have the occasional crave internally but when I smell smoke or when I'm around smokers it's NASTY. Seriously, when I walk in my mom's house (chain smoker) I almost get sick and I can smell the thick layers of smoke waffling at me.
That's the part that'll keep me from smoking -- the physical nastiness of the smell. Plus, I work on computers and opening a PC that's owned by a smoker is terrible -- I used to be one of those guys. Smoking 1-2 cigarettes an hour at my PC.....
I don't judge but if you can quit -- QUIT. Do drugs instead, at least they get you high!!
BTW: Don't worry about social situations. I am around smokers and I do not get the craving. I seem to only get my craving when I'm at home and I've done something that used to require a smoke (leave a big shit, eat a large meal, see someone smoking on TV, etc)
I'd say here lately 25/30 days I don't get any craving at all. Those 5 when I do it's just slight and I can ignore it with marijuana.
Side effects:
Weird dreams first 3-4 nights. I had two weird days in the middle of the Chantix treatment (10 total weeks) where I cried all damn day. I'm a male and this is atypical of my behavior but I don't even remember WHY (wasn't life changing) I just remembered I was balling my eyes out.
My mood changed but who knows how much is related to quitting something I had done for 10 years and how much was the pill. I told myself I was "qutting a drug" and that's a more powerful statement than "i'm quitting smoking."
You can probably quit without Chantix but if your friend has some left over go ahead and check them out. Most people can quit in 1-2 months but they really like to give them to you for 3-6 months.
It's all about confidence. Once you get past those first few days you feel GOOD.