Scientists Say: Nicotine

This substance is what makes it so hard to quit smoking or vaping

a photo of electronic cigarettes and regular cigarettes on a white background

Electronic cigarettes and regular cigarettes are two ways that people take nicotine, inhaling it in vapor or smoke.

Nehru Sulejmanovski/EyeEm/Getty Images Plus

Nicotine (noun, “NIH-coh-teen”)

Nicotine is an addictive substance found mostly in tobacco plants. In plants, it functions as an insecticide — poisoning insects that try to eat the plant. Humans, however, get very different effects from nicotine. It stimulates them, or makes them more alert. It relaxes them too. Unfortunately, nicotine is extremely addictive. The more someone uses it, the more they crave its effects. That makes it harder and harder to stop using it.

People take in nicotine in many ways. Many inhale it in smoke or vapor from cigarettes, cigars, pipes, hookahs or e-cigarettes. Others chew it in chewing tobacco. Almost 40 million adults in the United States smoke cigarettes. Another 4.7 million teens use a nicotine-containing product — usually cigarettes or vaping pods.

Some who are trying to quit smoking or vaping will use nicotine gum or skin patches. These give them a smaller dose of nicotine that might help make quitting for good a little easier.

In a sentence

If teens use vaping liquid with high levels of nicotine, they are more likely to become smokers.

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Bethany Brookshire was a longtime staff writer at Science News Explores and is the author of the book Pests: How Humans Create Animal Villains. She has a Ph.D. in physiology and pharmacology and likes to write about neuroscience, biology, climate and more. She thinks Porgs are an invasive species.