How many substances in a cigarettes?

Tobacco smoke contains over 4,000 different chemicals.

At least 50 are known carcinogens (cause cancer in humans) and many are poisonous.

Cigarettes are one of few products which can be sold legally which can harm and even kill you over time if used as intended. There are ongoing lawsuits in the USA which aim to hold tobacco companies responsible for the effects of smoking on the health of long term smokers.