Inclusion Criteria:

• Age 18-45. Individuals over the age of 45 will not be included as we are examining the effects of menstrual cycle and ovarian hormones.
• Daily smokers who smoke at least 10 cigarettes per day for at least past 6 months.
• Post menarche and pre menopausal
• Regular menstrual cycle between 25 and 35 days
• At least three months post delivery and breast feeding
• Desire to quit smoking and willingness to participate in a research study.
• Women with a history of depression (but not current MDE) and current PMDD will be included. Excluding women with these diagnoses would have a major impact on feasibility, but because both disorders might impact treatment outcome, individuals will be stratified across randomization groups.

Exclusion Criteria:

• Any unstable major axis I psychiatric disorder in the past month
• Current substance use disorders other than nicotine and caffeine use, in the past 30 days.
• Any medication that may interfere with psychophysiological monitoring
• Unstable medical or serious medical condition in the past 6 months
• Hypersensitivity to varenicline or TNP
• Use of other tobacco products
• Use of other medications with smoking cessation efficacy within 30 days prior to enrollment
• BMI less than 15 since this could alter hormone levels that affect menstrual phase
• Pregnancy
• Breast feeding
• Status post hysterectomy
• Birth control or HRT medication that would effect the menstrual cycle. Currently available oral contraceptives contain either a combination of a synthetic estrogen and synthetic progestin, or a progestin alone. Estrogen and/or progestin inhibit ovulation and alter cervical mucus and the endometrium by suppressing the production of follicle-stimulating hormone and the luteinizing hormone surge (Bucci & Carson, 1997)