Clinical Research Directory

Inclusion Criteria: * 21 years of age or older * Normal pulmonary and cardiovascular function with no history of COPD or cardiovascular disease (excluding hypertension) * Current exclusive use of a sub-ohm/mod or pod EC devices (≥ 1mL e-liquid/per day, ≥6 mg/ml nicotine concentration, EC for ≥ 1 year) * No plan on quitting nicotine use over the course of the study * All other forms of nicotine must be used \<5 days out of the past 28 days. * Able to read and write in English * Have access to email and a smartphone/computer that has reliable internet connection Exclusion Criteria: * Women who are pregnant and/or nursing or trying to become pregnant * Unstable or significant medical condition in the past 3 months (e.g., recent heart attack or other serious heart condition, stroke, severe angina) * Respiratory diseases (e.g., exacerbations of asthma or COPD, require oxygen, require oral prednisone), kidney (e.g., dialysis) or liver disease (e.g., cirrhosis), severe immune system disorders (e.g., uncontrolled HIV/AIDS, multiple sclerosis symptoms) or any medical disorder/medication that may affect participant safety or biomarker data * Uncontrolled substance abuse or inpatient treatment for that condition in the past 6 months * Have immediate family or household members currently participating in this trial