Nicotine is a stimulant, similar to other stimulants such as caffeine. The addictiveness in smoking apparently comes from (1) high dose absorbed rapidly, and (2

Nicotine is a stimulant, similar to other stimulants such as caffeine. The addictiveness in smoking apparently comes from (1) high dose absorbed rapidly, and (2) combination with other chemicals in tobacco and tobacco products. Nicotine addiction per se (or caffeine addiction) can be harmful to people, but the scale of harm is orders of magnitude away from the harms of smoking a pack of cigarettes a day. In small doses and in moderation, nicotine alone (e.g. taken as patch or gum) can be an effective medication, is not especially addictive, and has relatively mild side effects. https://www.gwern.net/Nicotine https://www.gwern.net/Nicotine Side effects of vaping should be studied more carefully (and the contents of vape fluid should be regulated): it is dramatically less harmful than smoking but plausibly still harmful. A massive quick dose of some stimulant (e.g. downing several espresso shots in a row) is not the most effective, and breathing stuff other than air is generally a bad idea.