Pharmacokinetics and Pharmacodynamics of Nicotine With Use of Standardized Research Electronic Cigarette (SREC) (SREC22)

Inclusion Criteria: Healthy on the basis of medical history and limited physical examination- Heart rate < 105 beats per minute (BPM)*. Systolic Blood Pressure < 160 and > 90*. Diastolic Blood Pressure < 100 and > 50*. *considered out of range if both machine and manual readings are above/below these thresholds. Body Mass Index <= 38.0. Current regular user of electronic cigarettes (EC) EC device use at least 15 or more days in the past 30 days (with e- liquid >= 3mg/ml) No restriction on flavor or type of e-cigarette used Saliva cotinine >= 50 ng/ml and/or NicAlert = 6 Age >= 21 years old <= 70 years old Willingness to abstain from drug use for the duration of the study Exclusion Criteria: The following unstable medical conditions: Heart disease Seizures Cancer Thyroid disease (okay if controlled with medication) Diabetes Hepatitis B or C or Liver disease Glaucoma Kidney disease or urinary retention History of stroke An ulcer in the past year Active use of an inhaler for Asthma or chronic obstructive pulmonary disease (COPD) Medications Use of medications that are inducers of nicotine metabolizing enzyme CYP2A6 (Example: rifampicin, carbamazepine, phenobarbital, and other anticonvulsant drugs). Use of sympatholytic medications for cardiovascular conditions including hypertension (Example: beta and alpha-blockers). Concurrent use of nicotine-containing medications (Example: nicotine patch, lozenge, gum). Any stimulant medications (example: Adderall) generally given for attention deficit hyperactivity disorder (ADHD) treatment. Other/Misc. Health Conditions Oral thrush Fainting (within the last 30 days) Other "life threatening illnesses" as per principal investigator and/or study physician's discretion Pregnancy Pregnancy (self-reported and urine pregnancy test) Breastfeeding (determined by self-report) Women of childbearing potential must be using an acceptable method of contraception Concurrent participation in another clinical trial. Inability to read and write in English Planning to quit smoking or vaping within the next 60 days A known propylene glycol/vegetable glycerin allergy Uncomfortable with getting blood drawn Recent onset or change (worsening) in cough, fever and/or abdominal symptoms (vomiting or pain) in the past two weeks