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The molecular structure of nicotine
  • Tobacco was brought to Europe from the Americas five centuries ago. It is now considered the world’s single biggest cause of preventable death.

    Tobacco is the herb Nicotiana tabacum. The plant makes the toxic substance nicotine as a chemical defence to stop insects eating it. It is possible that other chemicals in tobacco smoke may add to nicotine’s addictive effects (by disrupting the enzyme monoamine oxidase A).

  • By far the most popular and the most harmful way of consuming nicotine from tobacco is by smoking it. Smoking also seems to be the most addictive way of consuming nicotine, with fewer smokers being able to quit than people who use nicotine in other ways.

    Smoking Cigarettes

    Cigarettes are made of fermented, processed and dried tobacco leaves and stems (with some additives). Smoking them allows the nicotine to be absorbed into the blood through the lungs. Blood carrying nicotine reaches the brain within seconds, producing the mental effects smokers are after and satisfying nicotine craving in addicts. Unfortunately, as tobacco leaves burns, hundreds of harmful chemicals are created or released which are also drawn into the lungs. Half of the people who do not quit will die of a smoking-related disease. Smoke also drifts around, harming other people.

    Cigars and Pipes

    Cigars and pipes are alternative traditional ways of smoking. Some smokers of these do not inhale the smoke deeply into the lungs, but only draw it into the mouth. This causes less damage than cigarette smoking, although such smokers are still harmed by smoking. If users do inhale fully, the harms are likely to be similar to the harms of a similar amount of cigarette smoking.

    Hookah pipes (shisha)

    A hookah or hubble-bubble is a sort of tobacco pipe where smoke is drawn through a bottle of water. The tobacco (shisha) is flavoured and sweetened. People who smoke hookah regularly also have an increased chance of smoking related diseases such as lung cancer.

    Smoke-free tobacco and other nicotine-containing products

    Some forms of tobacco are not smoked, which prevents many, but not all of the harms of smoking. They confine the harm to the user, whereas smoking can harm others. Chewing or dipping tobacco, and snus (snus is illegal to sell in most of Europe) are products which release their nicotine into the mouth. The nicotine fix is achieved with less of the cancer-causing chemicals produced by burning and without the damage smoke causes to the lungs. Snuff is a powdered tobacco product which is inhaled up the nose, often making you sneeze. Whilst it increases the cancer risk for the places it contacts, the nose, mouth and throat, the overall level of risk of harm and death is also lower than with smoking cigarettes.

    In the last few years, there have been more products invented that contain nicotine extracted from tobacco. Lozenges, chewing gum and skin patches deliver doses of nicotine with a fraction of the harms associated with smoking. They are mostly used as ‘nicotine replacement therapies’ to help people wean themselves off cigarettes and eventually quit the drug entirely.

    Use of ‘electronic cigarettes’ is growing. These deliver a puff of vaporised liquid containing nicotine, which simulates smoking without burning. They have not been researched thoroughly, but it is very likely that they are much less harmful than actual cigarettes because they do not produce the range of damaging chemicals found in tobacco smoke, although they are not entirely harmless. It is still a matter of scientific and political controversy whether e-cigarettes and other alternatives to cigarettes can offer benefits to the health of society.

  • Because of its position in our culture, tobacco and the nicotine it contains is often not considered a mind-altering drug. In fact, nicotine affects the brain in several different ways and changes it over the long-term. Nicotine acts to increase the production of other chemicals in the brain known as neurotransmitters that affect brain function.  By causing the release of noradrenaline nicotine acts as a stimulant that produces a slight buzz. It is thought to cause improved focus by increasing acetylcholine, whilst its action in increasing beta-endorphin production relieves anxiety, giving nicotine some calming effects as well as stimulating effects. Nicotine also produces long-term effects on the dopamine system, which is involved in reward, mood and addiction.

  • Smoking

    Smoking is a very different experience depending on whether  you are a smoker or non-smoker.

    To a non-smoker, smoking can give a pleasant light-headed buzz, but smoke inhalation may be uncomfortable or painful, causing coughing, and making the user feel weak, dizzy and sick. Everyone responds to drugs differently; it seems that some people find their first cigarette revolting, and some find it rewarding, developing cravings in the first weeks of smoking. People who are naturally more sensitive to nicotine, who remember more of a hit of relaxation, dizziness and nausea from their first cigarette, seem more likely to get hooked, though everyone is vulnerable to tobacco addiction.

    To an addicted smoker who is tolerant of inhaling smoke, smoking satisfies a craving, may give a buzz, and can give a feeling of enhanced, calm focus. Smokers often say that cigarettes help them relax, but this is only half the story. In fact smokers are more stressed over the day than non-smokers because of their nicotine dependency, and the relaxation a cigarette gives is a temporary relief from that increased stress. After a cigarette, people who are addicted will begin the cycle of gradually worsening mood, increasing irritability and rising craving, until the next cigarette.

    The rituals of smoking, including rolling and lighting cigarettes, clipping cigars or preparing a pipe, become an important part of the experience and built into the craving.

    Smokeless alternatives

    The experience of using smoke-free alternatives varies depending on the speed with which the nicotine is delivered. Nicotine patches deliver the drug very slowly, which does the job of reducing cravings without giving the addictive little buzz that nicotine gives when it hits the brain in a rush. Inhaling on an electronic cigarette may be comparable to smoking in delivering nicotine to the brain. Chewing tobaccos, snus and nicotine gum are probably somewhere in between.

  • Currently nicotine has no medical use but it does have some useful properties and it, or related but less problematic substances  could be useful in the future in preventing or treating some conditions such as Tourette’s syndrome, depression, schizophrenia or Parkinson’s disease.

    It is suspected that many people with mental illnesses, especially schizophrenia, already use tobacco to control their symptoms. However, it is unlikely that any benefits of nicotine could be worth the harms of smoking. Smoking is one of the main reasons that people with schizophrenia live shorter lives on average.

  • With some drugs you risk harm each time you use them but with tobacco there is an enormous risk long-term, but little risk immediately apart from the chance of an unpleasant coughing fit.

    Nicotine is toxic, but it is difficult to imagine how anyone could accidentally ingest enough to be poisoned. The exception is children. Babies and toddlers have been poisoned by chewing cigarettes and swallowing nicotine products.

    Experimenting with taking multiple nicotine lozenges or similar things could be harmful or fatal and anyone suspected of having somehow consumed a nicotine overdose needs very prompt medical attention.

  • Smoking is associated with an increased risk of smoking-related diseases but if you already suffer from any heart problems, high blood-pressure, asthma or other lung problems, or come from a family where cancer or heart conditions are common, you are at even higher risk.

    For reasons that are not well understood, some mental health problems, like bipolar disorder and schizophrenia are heavily associated with smoking tobacco. If you have or have ever had one of these conditions, or if family members do, it is an extra reason to avoid ever starting to smoke, as addiction may be more likely.

  • Alcohol addiction and tobacco addiction are tightly associated, with a high proportion of people dependent on one substance also being dependent on the other. Alcohol seems to make people enjoy smoking more and a common trajectory of addiction is people just smoking when socialising and drinking then progressing to smoking all the time. The chance of mouth cancers is much higher in people who smoke and drink heavily, compared to people who use one but not the other drug.

    It is possible that brain changes caused by nicotine addiction increase the user’s sensitivity to the rewarding aspects of drugs or other addictive activities, make the user more vulnerable to addiction generally, adding more risk to the use of any other addictive substance.

    In the UK particularly, cannabis is often smoked with tobacco, even when the user does not otherwise smoke cigarettes. This is likely to cause preventable cravings for and addiction to either drug , especially the tobacco.

  • Smoking

    Nicotine is one of the most addictive drugs. Whilst people vary in their vulnerability to addiction, and a small minority of smokers seem to manage to have the occasional cigarette or cigar without becoming hooked, it is generally easy to become addicted and very hard to end an addiction. If you smoke, the Fagerström test can help you find out how addicted you are.

    Nicotine excites the brain’s reward circuitry, making cigarettes moreish, but as your brain re-tunes itself to having its chemistry altered over the long-term, the effect of going too long without putting nicotine in your brain becomes increasingly punishing.

    Social and cultural factors also make it easy to become a smoker and hard to quit. If you have smokers in your family or social circle you are more likely to end up addicted as you have the drug and drug use around you all the time. If you are trying to quit, or trying not to get into the habit of smoking regularly, friendly offers of a cigarette and seeing/smelling people smoking will make it really hard for you. Shops displaying cigarettes at the checkout make it easy to relapse into addiction.

    Smokeless alternatives

    There is strong evidence that nicotine replacement with patches, lozenges, gum etc. can help some people stop smoking, and eventually quit nicotine entirely. Quitting smoking but remaining addicted to nicotine delivered through these products is much healthier than smoking, though not as healthy as quitting nicotine entirely.

    Different forms of nicotine and tobacco product will differ in their addictiveness even though the drug chemical is the same in all of them. Products which deliver a nicotine hit fast, like cigarettes and e-cigarettes, are likely to be more addictive than those which deliver nicotine slowly.

    Alternatives to smoking, like e-cigarettes and snus are not as well studied as cigarettes.  It is almost certain that they are less harmful than cigarettes. However, people who don’t use nicotine and wouldn’t smoke could find these appealing, leading to new nicotine addictions. The process of becoming addicted to cigarettes requires the user to desire each cigarette more than they dislike the effects or fear the results. Alternatives which are less unpleasant than inhaling irritating, hot smoke may smooth the path to addiction. The marketing of fruit-flavoured e-cigarettes can be compared to the development of alcopops, which use appealing flavours to bypass the protective disgust people (especially the young) feel when tasting ethanol.

  • Nicotine withdrawal can be very unpleasant, but is not physically harmful. Just a couple of hours after having a cigarette, someone dependent on nicotine will begin to feel fidgety and stressed, craving the drug, and their heart-rate will rise. Rates of relapse after quitting are extremely high.

  • There are no other legal products which are as harmful as cigarettes when used as they are designed to be used. Smoking causes gradual damage to your body as well as increasing the risk of various diseases. It also harms other people who breathe the smoke. Below is just a selection of the harms of smoking. Most of these harms are not known to apply to smokeless nicotine products.

    Quality of Life

    Smoking damages many aspects of your quality of life as well as increasing the chance of an early death. It reduces physical fitness, making you get out of breath easily, it damages your lung’s ability to self-clean, so you may cough heavily, especially the morning. It is a major cause of male sexual dysfunction (by damaging blood-flow in the penis). Yellowing and ageing of teeth, hair and skin may mean smokers feel less attractive and the lingering smell of tobacco smoke on clothes and in homes is very unattractive to most non-smokers. Successful public health campaigns have had the side-effect of making some smokers feel guilty and stigmatised. There can be unexpected consequences, for example it may be impossible to adopt children if you smoke. It is also very expensive. Being addicted to other nicotine products may have some smaller impacts.


    Around 7 in every 8 cases of lung cancer and 3 in 4 cases of oral cancer are caused by tobacco, but as well as these more obvious cancers in places the smoke contacts directly, it increases the chance of many others too, such as cervical and pancreatic cancer.

    Lung disease

    Smoking destroys the tiny hairs which sweep mucus up out of the lungs, allowing gunk-like mucus and tar to collect. This increases the chance of infections, and causes persistent coughing. The delicate air sacs in the lungs can break down. Chronic Obstructive Pulmonary Disease (COPD) is the term used for the often fatal disease of the lungs with progressive loss of function caused by smoking. This can potentially spoil your life long before it causes death.

    Cardiovascular disease

    Smoking increases the risks of heart disease, raises blood pressure and damages veins and arteries. This means that the risk of heart attacks and strokes is much increased.

    Risk of breaking bones

    One of many little-known risks of smoking is that it interferes with the mineralisation of bone, particularly in young women who should be storing up the strength of their ‘bone bank’ for when bones lose density in later life. Smoking leaves bones (notably hips and backbones) a little weaker and so significantly more likely to fracture, especially in older age. After quitting, it seems that bone density recovers fairly well.


    • Avoiding addiction to smoking tobacco in the first place,

    • If addicted already, quitting as soon as possible

    • If quitting is not feasible or desired, transferring to less harmful forms of nicotine product.

    Historical attempts to develop ways for people to continue smoking cigarettes whilst reducing overall harm, for example by using low-tar varieties, have proved ineffective.


    Quitting smoking permanently can be really hard, and many people do not succeed on their first attempt. It is possible for motivated people to quit smoking without any help, either by cutting down gradually or just deciding to never smoke again, called ‘going cold turkey’. There is some evidence that ‘going cold turkey’ is the most likely to work overall, though different methods will work best for different people.

    Depending on where you live, there are a range of sources of support to help you quit, from doctors to other community services. The support of family and friends is also helpful.

    Nicotine replacement therapies, like patches and nicotine gum, are proven to help some people quit. They may help get out of the habits involved in smoking, allowing you to overcome the nicotine addiction separately.

    Switching to smokeless nicotine

    Quitting tobacco is the way to minimise harm, but in reality, many people struggle and fail to quit, or do not want to. These people may benefit from switching to a form of long-term nicotine addiction which is less likely to cause disease and death. There is very little evidence yet to rank the forms of smokeless tobacco in order of harmfulness, but it is likely that they all offer far less risk than smoking cigarettes.

  • Smoking reduces stress

    Nicotine does make you relax, but nicotine addiction causes stress and worsening mood the longer it has been since the last cigarette, so in fact, a smoker suffers more stress than a non-smoker.

    Occasional or ‘social’ smoking is harmless

    Whilst occasional smoking is far less harmful than heavy smoking, any amount of smoking increases the risks of suffering from a huge range of diseases, many of them fatal. Occasional smoking is also highly likely to end in regular smoking. Talk to people who are addicted; many smokers who thought they were in control of their habit eventually lost control.

    Nicotine itself is harmless, it’s the smoking that does the damage.

    This is not that far from the truth; the vast majority of the harms of cigarettes are not caused by nicotine (although you could argue that nicotine is the ultimate cause as it keeps smokers smoking). However, it is important not to disregard nicotine and think that e-cigarettes and similar alternatives to smoking are totally harmless. Nicotine has harmful effects on blood vessels and its many effects on the brain, including addiction, can negatively affect your mood and could alter your behaviour towards other addictive substances or activities.

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