E-Cig flavor showdown: do menthol and tobacco hook smokers differently?

Copied word for word from the study's registry entry, so the wording is the study team's rather than ours.

Inclusion Criteria: * healthy (determined by self-report) * at least 18 years old * willing to provide informed consent * able to attend the lab and use designated products according to the study protocol * smoke cigarettes at least 3 days per week, and on those days, at least one cigarette is smoked per day * positive urine cotinine test Exclusion Criteria: * Women who are breastfeeding or test positive for pregnancy (by urinalysis) at screening. * Individuals with the following self-reported current, diagnosed medical condition(s) will be excluded automatically: uncontrolled high blood pressure (via self-report or observed at screening; BP must be less than 160/100), heart-related conditions (e.g., recent heart attack/stroke, coronary heart disease), severe immune system disorders (e.g., HIV/AIDS, multiple sclerosis), respiratory disorders (e.g., COPD, asthma), kidney diseases, liver diseases (e.g., cirrhosis), or seizures. * Individuals with other self-reported current, diagnosed medical conditions (e.g., diabetes, thyroid disease, lyme disease) will be considered for exclusion after consultation with the PI and medical monitor. We ask a variety of questions about participants' medical conditions that are not necessarily exclusionary to be able to consult with the medical monitor about these conditions. Participants with any medical condition/medication that may affect participant safety, study outcomes, or biomarker data will be excluded based on these consultations. * Individuals with current, diagnosed, uncontrolled psychiatric conditions will be excluded. A controlled psychiatric illness is defined as one where the individual is taking medication and/or receiving other treatment (e.g., psychotherapy). In addition, individuals who have been to the ER and/or been hospitalized for a psychiatric condition in the past year will be excluded. Individuals with past-month use of cocaine, opioids, benzodiazepines, and methamphetamine or other illegal substances (other than cannabis) will be excluded. Individuals who report using cannabis more than 15 days in the past 30 and/or alcohol more than 25 days in the past 30 days will be excluded. * Participants who choose not to answer questions related to inclusion/exclusion criteria will be excluded. * Participants who indicate their sex assigned at birth is female will be excluded if they are breastfeeding or test positive for pregnancy (by urinalysis) at screening.