Efficacy of Varenicline for Smokeless Tobacco Use in India

Inclusion Criteria: * males and females * over age 18 * used smokeless tobacco every day for the past year (confirmed with urinary cotinine) * residing within 100km of New Dehli for the next 4 months * interested in quitting use of smokeless tobacco. Exclusion Criteria: * currently enrolled or plan to enroll in another tobacco cessation program in the next 4 months * plan to use other smoking cessation treatments in the next 4 months * smoke cigarettes * have current substance abuse (e.g., opioids, cocaine, marijuana) verified by urine drug screen * have current (last 6-months) alcohol consumption that exceeds 25 standard drinks/week (if past abuse, must be symptom free for ≥ the past 12 months) * Current use or discontinuation within last 14 days of: 1. smoking cessation medications (bupropion, Varenicline, NRT); 2. antipsychotics, atypicals, mood-stabilizers, anti-depressants (tricyclics, SSRIs, MAOIs), anti-panic agents, anti-obsessive agents, anti-anxiety agents, stimulants; 3. Anti-coagulants; 4. Daily medication for asthma or diabetes (eligible with physician approval); * are pregnant, planning a pregnancy, or lactating * have a history or current diagnosis of psychosis, general anxiety disorder,bipolar disorder, or schizophrenia * have a current diagnosis of depression (if past diagnosis, must be symptom free for ≥ the past 12 months) * have an allergy to Varenicline * ever contemplated or attempted suicide * have serious/unstable disease within the past 6 months (e.g., cancer \[but melanoma\], heart disease, HIV/AIDS) * have a history of epilepsy or seizure disorder * have a history or diagnosis within the last 6 months of abnormal rhythms and/or tachycardia (\>100 beats/minute) * have a history or current diagnosis of COPD; cardiovascular disease (stroke, angina); heart attack in the last 6 months; and/or uncontrolled hypertension (SBP\>150 or DBP\>90)16) * have a history of kidney or liver failure * have any medical condition or medication that could compromise safety as determined by a study physician * cannot provide informed consent or complete the study tasks as determined by the Principal Investigator or study physician.