How bad is nicotine?

The harm of nicotine is complex, and the key lies in understanding the difference between it "in itself" and "as a component of tobacco or e-cigarettes".

In simple terms: Nicotine itself is the main culprit causing tobacco addiction, having various direct negative effects on the human body, but its harm is far less than the thousands of other toxic substances produced by the burning of tobacco.

 The harm of nicotine "in itself"
High addiction: This is the main hazard of nicotine. It stimulates the brain to release dopamine, generating a sense of pleasure, thereby forming dependence. Its addiction is considered to be second only to heroin and cocaine. Once addicted, withdrawal symptoms such as intense craving, anxiety, depression, irritability, and lack of concentration will occur.

Cardiovascular system damage: A large number of studies have confirmed that nicotine itself is a cardiovascular toxin.

Short-term effects: It immediately causes an increase in heart rate, blood pressure, and vasoconstriction.

Long-term effects: Continuous stimulation promotes hypertension and atherosclerosis, thereby increasing the risks of heart disease, stroke, etc.

Harmful to the development of the brain of teenagers: For the developing brain of those under 25 years old, the harm of nicotine is particularly severe.

Impair cognitive functions: Affecting attention, learning ability, and memory.

Increasing future risks: Early use of nicotine significantly increases the risk of developing dependence on other substances in the future.

Harm to pregnant women and fetuses: Nicotine is toxic to fetal development. It passes through the placental barrier and affects the development of the fetus's brain and lungs, increasing the risks of premature birth, low birth weight, etc.

The difference between nicotine and the "harm of tobacco/e-cigarettes"
Many people confuse the harm of nicotine and smoking. These are two completely different concepts.

Nicotine ≠ The entire harm of tobacco combustion: The reason smoking is fatal is not mainly because of nicotine, but the over 7,000 chemical substances produced when tobacco burns, among which at least 70 are known carcinogens. These substances are the direct cause of most tobacco-related diseases and deaths.

Regarding the claim that "the risk of nicotine itself is small": The UK Public Health Department and other institutions did once state that "the direct risk to health from nicotine is very small". But please note that this conclusion has strict context:

It is relative to smoking, aiming to indicate that the harm of nicotine replacement therapy (such as patches, gum) is much less than smoking.

It does not mean that nicotine is safe. Subsequent studies have clearly pointed out that nicotine itself is a cardiovascular toxin.

This conclusion holds true under the premise of pure nicotine and not through inhalation. The long-term effects of e-cigarettes, which are heated and inhaled, remain unclear.

Summary
The harm of nicotine is multi-dimensional:

It is the main culprit causing tobacco addiction.

It itself will damage the cardiovascular system.

It has clear harm to the brain development of teenagers and the development of the fetus.

Although its harm is far less than the toxic mixture produced by the burning of tobacco, it is by no means harmless.

If you do not smoke, the healthiest choice is never to come into contact with any form of nicotine. If you are smoking and considering quitting, using nicotine replacement therapy (such as patches, gum) is a scientific method with much lower risk than continuing to smoke, and it is recommended to do so under the guidance of a doctor.