What's REALLY in your cigarette or vape? You're not just inhaling nicotine. Cigarettes contain arsenic, ammonia, and formaldehyde yes, the same stuff used to embalm bodies. Vapes? Heavy metals, toxic chemicals, Construction of electronic cigarettes Wikipedia The Truths Behind Vaping: Information for Youth and Teens USU E cigarettes emit very high formaldehyde levels only in conditions that are aversive to users: A replication study under verified realistic use conditions ScienceDirect