Nicotine has a bad reputation — and is often confused with 'everything that is bad in a cigarette'. The reality is more nuanced: it is an addictive substance, but not the direct cause of cancers, strokes or COPD. The distinction changes everything, particularly when you want to understand why vaping and nicotine replacement therapies actually work.

What nicotine actually is

Nicotine is an alkaloid produced by plants of the Nicotiana genus (tobacco, but also, in much smaller quantities, tomatoes, aubergines and potatoes). It was identified chemically in the 19^th century. Its structure looks like a natural neurotransmitter in the brain, acetylcholine — which is why it can lock into the brain receptors known as 'nicotinic'.

Nicotine on its own — what it does

At moderate doses, pure nicotine (separated from tobacco) has well-documented effects:

On the 'drug' side: what is undisputed

Nicotine addiction is among the most powerful documented in pharmacology. Its addictive potential is comparable to that of cocaine or heroin in several neuroscience studies — which does not mean the social or physical effects are equivalent, but that the brain mechanism of getting hooked is just as intense.

On the 'medicine' side: therapeutic uses

Myth vs reality

Why nicotine alone is not the public enemy

Tobacco contains more than 7,000 substances, including 70 known carcinogens according to the WHO. Nicotine, by contrast, is a single molecule whose effects are now well mapped. Without combustion:

• No tar → no tobacco-related cancers.

• No carbon monoxide → no tissue asphyxiation.

• No fine particles → far less respiratory damage.

What remains is nicotine itself, which mostly causes two issues: addiction and vasoconstriction (an effect on the blood vessels). For non-smokers, the ideal is still none at all. For smokers who cannot manage to quit, isolated nicotine (vape, replacement therapy) is a much less dangerous compromise than continuing to smoke.

What about acute toxicity?

At very high doses, nicotine is toxic. The lethal adult dose has been debated (long set at 60 mg, now estimated by some researchers at between 500 and 1,000 mg). The most worrying incidents are accidental ingestions of concentrated vape liquid by children — that is why child-resistant caps matter, along with storing it out of reach.

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