Recent research suggests that a new combination therapy may be especially effective in increasing long-term abstinence from smoking. A key purpose of the proposed study is to examine what types of tolerability concerns, if any, emerge from the simultaneous use of three FDA-approved cessation medications (varenicline, nicotine patch, and nicotine lozenge) and the timing of those events, in order to better assess how the use of this combination of tobacco cessation medicines can be most effectively and safely delivered and monitored. Study participants will take the three medications for 12 weeks in a manner consistent with labeling. Adverse events will be assessed at all study visits.