This study will evaluate a reward devaluation strategy in which smokers use the JUUL e-cigarette immediately before any combustible cigarettes (CCs) are smoked. This procedure is predicted to accomplish three goals: 1) the rewarding effects of CC will be disrupted because subjects will already have attained fairly high peak nicotine concentrations immediately before smoking the cigarette. This reduces the rewarding effect of smoking, in part from receptor desensitization that occurs following nicotine exposure, which reduces the response to a subsequent dose of nicotine, and in part from satiating the drive to smoke; 2) the use of the JUUL will become associated with the same cues that elicit smoking, thereby promoting the substitution of JUUL use for CC use; and 3) ad libitum nicotine intake from the JUUL and its rewarding effects will be maximized because, unlike CC, they will be experienced after a period of nicotine deprivation. Thus, despite a lower per-puff nicotine dose relative to CC, the pharmacologic impact and reinforcing effect will be maximized. The study will evaluate two flavors (Mint and Virginia Tobacco), randomly assigned, to determine if flavor assignment (similar to the subjects' usual brand of CC or different than the subjects usual brand CC) has an effect on the success of this reconditioning procedure.

Inclusion Criteria:

1. Has signed the ICF and is able to understand the information provided in the ICF.
2. Is 21 to 65 years of age (inclusive) at screening.
3. Smokes ≥ 10 commercially available CCs per day (no brand restrictions), for the last 12 months.
4. Expired air CO reading of at least 10 ppm as assessed at the screening session.
5. Interested in switching to an electronic cigarette.
6. Willing and able to comply with the requirements of the study.
7. Owns a smartphone with text message and data capabilities compatible with necessary surveys.

Exclusion Criteria:

1. Is unhealthy or cannot participate in the study for any reason (e.g., medical, psychiatric, and/or social reason) as judged by the Investigator or designated medical staff based on all available assessments from the screening period (e.g., safety laboratory, vital signs, physical examination, ECG, concomitant medications and medical history).

2. PHQ-9 score greater than 9, or a score greater than 0 on item #9 ("Thoughts that you would be better off dead, or of hurting yourself in some way") at screening.

3. Planned use of an FDA-approved smoking cessation product during the study.

4. High Blood Pressure (systolic >150 mm Hg, diastolic >95 mm Hg) at screening.

5. Body mass index (BMI) less than 15.0 kg/m2 or greater than 40.0 kg/m2.

6. Coronary heart disease, structural cardiac disease (including, but not limited to valvular heart disease or cardiac murmurs), cardiac dysrhythmias, syncope, cardiac chest pain, or history of heart attack or heart failure.

7. Has received psychotherapy or behavioral treatments within 30 days of screening, or during the study.

8. Taking antidepressants or psychoactive medications (e.g. antipsychotics, benzodiazepines, hypnotics).

9. Use of any of these products in the past 30 days:

   1. Illegal drugs (or if the urine drug screen is positive for cocaine, THC, amphetamines, methamphetamines, or opiates);
   2. Experimental (investigational) drugs that are unknown to the subject;
   3. Chronic opiate use.

10. Use of smokeless tobacco (chewing tobacco, snuff), cigars (except for "Black & Mild" cigars or Cigarillos), pipes, hookah, e-cigarettes, nicotine replacement therapy or other smoking cessation treatments within 14 days of screening.

11. Pregnant or nursing (by self-report) or positive pregnancy test.

12 weeks