What parents need to know and do about e cigarettes Harvard Health Guidance for Healthcare Providers on Evaluating and Tracking Patient Use of E Cigarettes or ENDS Products American Lung Association Vaping MouthHealthy Oral Health Information from the ADA Vaping vs Smoking vs IQOS: Which is Least Harmful? Scripps Health E cigarettes remain the most commonly used tobacco product among middle and high school students in the United States, according to the Instagram What Is IQOS, and How Is It Different from Vaping or Smoking?