Varenicline is to be started one week prior to the smoking cessation quit date. Hajek et al randomized patients to take Chantix or placebo as a run-in for 3 weeks prior to that. All patients took varenicline for 1 week prior and 3 months after quitting. Those who were "preloaded" had 12-week abstinence rates of 47%, vs. 21%, p=0.005. Arch Int Med 2011;171:770-777.