What Substances do Cigarettes Contain?

There are many substances that cigarettes contain, and at least 250 of them are harmful to your health. In this article, we'll tell you which are the most dangerous components and how they can affect your health.
What Substances do Cigarettes Contain?
Leonardo Biolatto

Written and verified by the doctor Leonardo Biolatto.

Last update: 27 May, 2022

Among the substances cigarettes, contain are nicotine, tar, and hydrogen cyanide gas. All of them are toxic and cause your health to deteriorate seriously, so experts consider them to be risk factors for multiple illnesses.

There are 4,000 chemical elements in the smoke emanating from a cigarette, and among them, some 50 are carcinogenic. However, cancer isn’t the only final harmful effect of smoking. It’s also associated with pulmonary and cardiovascular diseases.

The main reaction released by the substances that cigarettes contain is combustion, so toxic smoke doesn’t only come from ordinary cigarettes. All types of tobacco, to a greater or lesser extent, represent a risk factor when you smoke them.

The three most relevant substances that cigarettes contain

We can mention three main toxic chemicals in tobacco smoke: Nicotine, carbon monoxide, and tar. For all three, there’s sufficient evidence regarding their seriously harmful effect on human health.


Nicotine is the most well-known substance that cigarettes contain. Its absorption is rapid and it can reach the brain in less than 10 seconds. Once there, it stimulates neurons to produce the neurotransmitter dopamine.

Through dopamine, nicotine sustains the cigarette addiction circuit. At the same time, tolerance and abstinence appear; the first is the need for more and more doses to sustain the effect of satisfaction, and the second is the set of symptoms that become present when you discontinue the addictive substance.

Nicotine is a central nervous system stimulant. When it comes to the heart, it increases the heart rate, affecting blood pressure.

A man lighting a cigarette.
Cigarette smoke is the vehicle for toxic substances that arise from combustion.

Carbon monoxide

Cigarette smoke contains carbon monoxide. This is the same substance that appears in a toxic form after the combustion of automobile engines.

Carbon monoxide displaces oxygen from hemoglobin and competes with it for its place in the blood. Therefore, smokers reduce their oxygen-carrying capacity compared to non-smokers.


What we mention tar, we’re talking about a generic term to refer to many toxins that fall into the same category. This group of chemicals is responsible for tobacco-stained teeth.

Tar is progressively deposited in lung tissue. And when you exceed 20 cigarettes a day, the accumulation is around 500 grams in a year, which is the primary risk factor for the cellular changes that lead to lung cancer.

Other substances that cigarettes contain

We can mention other substances that cigarettes contain that are harmful to health.

  • Ammonium: Manufacturers include ammonium in cigarettes so that nicotine crystallizes. The tobacco industry’s objective is to get nicotine into the body faster, and that is why they add this harmful substance. By alkalinizing tobacco smoke, the penetration of nicotine becomes more efficient.
  • Hydrogen cyanide gas: In the invisible part of cigarette smoke is hydrogen cyanide gas. It also competes with oxygen, so it contributes to the low oxygenation of smokers. It has high carcinogenic power, as it stimulates cell mutation.
  • Tobacco waste: The filling of cigars is completed with the remains of tobacco, which are not the leaves, but the waste from its production. Flavorings are added to this filler to make consumption more pleasant. These additives include chemicals that are also harmful.
Lung cancer in women can be deadly
Cigarettes have no beneficial effects on health, and on the contrary, are capable of causing cancer.

Find out more: Warning: Smoking Can Affect The Eyes

Cigarettes don’t contain any healthy substances

Among the substances that cigarettes contain, there’s not one that we can describe as healthy. Even chemicals that are harmless by themselves, in the context of cigarettes, acquire a negative connotation because they contribute to the eventual carcinogenic effect on human cells.
Smoking is the cause of one-third of cancers in the world. It’s not only responsible for lung cancer, but also participating in the development of esophageal, mouth, colon, pancreatic, and bladder cancers. We can also trace some forms of leukemia back to tobacco.

Another issue is that of passive smokers, who are harmed by the smoke they inhale because of others. As we said, combustion expels toxins through the smoke, which travels through the air and is deposited on surfaces, from where it also causes harm.

In short, there are no healthy substances contained in cigarettes. It’s important to understand this to recognize that advertising messages advocating moderate consumption are in fact myths.

All cited sources were thoroughly reviewed by our team to ensure their quality, reliability, currency, and validity. The bibliography of this article was considered reliable and of academic or scientific accuracy.

  • Ruiz, A. Martín, et al. “Efectos tóxicos del tabaco.” Revista de toxicología 21.2-3 (2004): 64-71.
  • Valero, F. Carrión, and JR Hernández Hernández. “El tabaquismo pasivo en adultos.” Archivos de Bronconeumología 38.3 (2002): 137-146.
  • Cabanes Domenech, Anna, et al. “La situación del cáncer en España, 1975-2006.” (2009).
  • Fernández González, Elmo Manuel, and Dariel Adrián Figueroa Oliva. “Tabaquismo y su relación con las enfermedades cardiovasculares.” Revista Habanera de Ciencias Médicas 17.2 (2018): 225-235.
  • Martín de Diego, C. E., et al. “Valor de la proteína C reactiva según historia de tabaquismo y composición de nicotina y alquitrán.” Anales de medicina interna. Vol. 23. No. 1. Arán Ediciones, SL, 2006.

This text is provided for informational purposes only and does not replace consultation with a professional. If in doubt, consult your specialist.