Exploring the Impact of Two-week Kava on the Metabolism of Nicotine and NNK

Inclusion Criteria: Individuals eligible for study participation must meet the following criteria: * Must be a current smoker with history of head and neck cancer. * Must be at least 3 months out from completing definitive cancer treatment. * Must not be undergoing active treatment for cancer or have known recurrence. * Subjects must have adequate organ function, as defined by: the clinical chemistry analysis of ALT, ALP, AST and total bilirubin within the normal range. * Subjects must have access to a functional telephone. * Written informed consent obtained from the subject or the subject's legal representative and the ability for the subject to comply with all the study-related procedures. * Women of childbearing potential (WOCBP) must be using an adequate method of contraception to avoid pregnancy throughout the study. Prior to study enrollment, women of childbearing potential must be advised of the importance of avoiding pregnancy during trial participation and the potential risk factors for an unintentional pregnancy. WOCBP include any woman who has experienced menarche and who has not undergone successful surgical sterilization (hysterectomy, bilateral tubal ligation, or bilateral oophorectomy) or who is not post-menopausal. Post-menopause is defined as: * Amenorrhea that has lasted for ≥ 12 consecutive months without another cause, or * For women with irregular menstrual periods who are taking hormone replacement therapy (HRT), a documented serum follicle-stimulating hormone (FSH) level of greater than 35 mIU/mL. * Males with female partners of child-bearing potential must agree to use physician-approved contraceptive methods (e.g., abstinence, condoms, vasectomy) throughout the study. Exclusion Criteria: Subjects with any of the following will not be eligible for study participation: * Known liver disease as defined by the following elevated serum levels of AST, ALK Phos, ALT or total bilirubin: * Consumption of more than three alcoholic drinks per day * D. Subjects must not have been diagnosed with any liver dysfunction * Subjects who regularly take more than the recommended dose of acetaminophen for pain management. * Females or males of childbearing potential who are unwilling or unable to use an acceptable method to avoid pregnancy for the entire study period. * Females who are pregnant or breastfeeding. * History of any other disease, metabolic dysfunction, physical examination finding, or clinical laboratory finding giving reasonable suspicion of a disease or condition that contraindicates the use of protocol therapy or that might affect the interpretation of the results of the study or that puts the subject at high risk for treatment complications, in the opinion of the treating physician. * Prisoners or subjects who are involuntarily incarcerated. * Subjects who are compulsorily detained for treatment of either a psychiatric or physical illness. * Subjects demonstrating an inability to comply with the study and/or follow-up procedures.