Each session will last approximately 6.5 hours and will correspond to a transdermal patch dose (0 or 21mg) and cigarette type (denicotinized and nicotinized). Objectively verified cigarette abstinence will be required before each session. Sessions will occur at least 48 hours apart to avoid carryover. At the beginning of each session a patch will be placed on the participant's back and at 4, 5, and 6 hours after patch application the participant will smoke a cigarette (all identifying marking on the cigarette will be covered for blinding purposes). Physiological, subjective, cognitive, and smoking behavior outcomes will be collected during study visits.