Nicotine

Nicotine is the addictive chemical in tobacco, and in most vapes, pouches, and cigarettes. Modern vapes and pouches use nicotine salts, which go down smoother than older forms. There's less harshness to make you stop, so it's easy to take in a lot more than you would from a cigarette.

In 2024, about 1.63 million US middle and high school students (5.9%) were using e-cigarettes. That's down from more than five million in 2019, but vaping is still the tobacco product teens use most.

Inhaled nicotine reaches the brain in about ten seconds. Drugs that hit the reward system that fast tend to be the most addictive.

It binds to α4β2 acetylcholine receptors and triggers dopamine in the brain's reward circuit. Dopamine isn't the pleasure itself; it's the signal that tells your brain a behavior is worth repeating. Do it enough and your brain dials its own dopamine down to compensate. Normal starts to feel flat, and you need nicotine just to feel even.

A short burst of alertness, a small lift in mood and focus, less appetite, and a rise in heart rate and blood pressure. Once you're dependent, the focus you feel is mostly relief from the last dip, not a real gain over where you'd be without it.

The brain keeps developing into your mid-20s, and it's especially sensitive to nicotine during that time. Using it in these years can affect attention, learning, mood, and impulse control, and can make the reward system more reactive to other drugs later on.

Dependence can set in fast. Some of the most at-risk teens report losing control over their use within a day or two of first trying it. That's how the drug acts on a developing brain, not a matter of willpower.

Nicotine raises your heart rate and blood pressure and is highly addictive. Vape aerosol also isn't water vapor. It carries ultrafine particles and other compounds into your lungs, and the long-term effects are still being studied.