What is vaping? What are e cigarettes? Is it as harmless as it is made out to be? The truth is many e cigarettes contain nicotine, a highly addictive substance that can affect brain What Does Puffs Mean in Vape? SMPO About E Cigarettes (Vapes) Smoking and Tobacco Use CDC Vaping an overview ScienceDirect Topics Vapes and e cigarettes often contain nicotine, heavy metals, and carcinogensand can harm developing brains, affect mood and learning, and lead to lasting lung damage. Just one hit can start an addiction.