The effects of nicotine itself are similar to that other popular drug, caffeine. See our (nicotine reading list.) There is no evidence that nicotine causes any substantial risk for cancer, and the research shows that the risk for cardiovascular disease is minimal. The confusion about nicotine comes from anti-smoking activists talking about nicotine and smoking as if they were the same. While it is true that people smoke mostly because of nicotine; nicotine users die mostly because of the smoke.
Neither nicotine nor coffee are completely benign (in particular, both cause a short-term increase in your blood pressure and pulse rate when you use them, which could affect your health). A lot of evidence shows that coffee drinking causes very little health risk. Studying nicotine is a bit harder, because most nicotine users smoke, and the smoking is quite bad for you. But there is some good evidence: If nicotine were very bad for you then smokeless tobacco, which provides nicotine, would be very bad for you. As we've shown elsewhere, that is not the case.
Though nicotine is relatively safe for most individuals, it may have a negative effect on fetal development and as such should be avoided during pregnancy.
That question is a bit tricky to answer, since there is not actually a scientifically accepted definition of addiction. We know that some people try hard to give up nicotine and keep going back to it, which probably meets most people's definition of addiction. Indeed, that is a large part of why we think harm reduction is such an important idea. If everyone who used nicotine could just take it or leave it, then some anti-tobacco advocates' goal of getting everyone to just quit would not be so absurd.
Many people can take or leave it, so nicotine is clearly not a strong draw for some people. Many tobacco users have not had too much trouble quitting, and many others use it sometimes, but not regularly. Some of the researchers who produced this website use ST sometimes; we feel it is our professional responsibility to be familiar with the products we write and talk about but feel no urge to use it more often. It seems that some people get substantial benefits that keep them using nicotine, while others do not.
Some advocates seem to think that addiction is a terrible disease in itself (despite them not even having a good definition for it). If you are addicted to something, these people think you should give it up, even if it is doing you more good than harm. They apparently would have you suffer the pain of quitting, and possibly ongoing unpleasantness of wanting something you cannot have just because you are "addicted". We think this is absurd, and even downright cruel. We agree that when someone is obsessed with something and neglects the rest of their life, or is compelled to do something that hurts them, then helping them quit is a worthy goal. But when someone has a habit that is not hurting them much, then why should we make their lives miserable and insist that they give it up. Of course, smoking does hurt people a lot, but nicotine does not have to.
It is sad and frustrating that some people are so obsessed with ending addiction to nicotine, rather than reducing the heath impact of using nicotine, that they tell all tobacco users that they must quit entirely, and if they do not quit, they might as well smoke and die from it. In addition to insisting that people endure the unpleasantness of quitting, this has terrible health consequences. Since many people who try to quit smoking fail, this attitude dooms millions of people to die unnecessarily from their nicotine habit.
For quite a few people, nicotine provides the benefits that some people get from caffeine or Ritalin: it helps them focus and be more productive, overcoming attention-deficit-type problems. For some people, nicotine provides relief from stress, anxiety, or panic. For people suffering from some severe mental illnesses, nicotine seems to provide great relief, which probably explains why a very large fraction of psychiatric patients smoke.
Nicotine is also suspected as the reason for the lower incidence of Parkinson's Disease among smokers. And for those who have it, nicotine appears to reduce the associated symptoms. Unfortunately, because nicotine is so stigmatized, there is less information about it than we might want, so we do not have good scientific evidence on all of its possible benefits.
At the risk of being politically incorrect, we will state the obvious: Benefits are a good thing. Many people recognize that they get immediate psychological benefits from nicotine (anything from being able to focus in school to not feeling severe distress) and, not surprisingly, keep using it. Think about this: Most everyone in Western society tries nicotine sometime during their childhood or adolescence, but relatively few of them adopt it as a habit. Doesn't it make sense that those who kept using felt substantial benefits from it, while those who did not take it up did not?
One of us had a friend in graduate school who had forced himself to quit smoking because of the health risks. He believed that if anyone found a way to provide nicotine without large health risks, then everyone in school would use it. He thought that if they wanted to stay competitive, they would need the increased clear thinking and productivity that he experienced with nicotine. He did not know that there was, in fact, a way to get nicotine without a huge health risk (none of us did). More interestingly, he did not realize that most of us did not get the same benefit from nicotine that he did. He assumed everyone was like him. Tobacco policy seems to be made by people who have not experienced any benefits from tobacco, and assume that everyone is like them.
People who get the most benefit from smoking are the ones who are likely to keep smoking (be "addicted") despite high taxes, non-smoking buildings, and all the messages telling them to quit. So, by making smoking more and more unpleasant, while also trying to hide the fact that there are much safer sources of nicotine, anti-tobacco advocates are just hurting people who get relief from psychological difficulties by using nicotine. Laws against smoking in public places are often praised by anti-smoking advocates for making it easier for smokers to quit. But when you start pretending that smoking has no benefits, it becomes clear that making quitting "easier" really means making smokers' lives so unpleasant that the costs exceed the benefits, even when the benefits were high.
We can't know whether the benefits of using nicotine outweigh the costs of buying it, the effort that goes into using it, and the possible very small health costs, for any particular person. This is a decision that people must make for themselves, and should do so based on mature judgment, a full understanding of the true costs, and knowledge of their own personal benefits.
Advocates should keep in mind that some nicotine users are getting benefits that make them willing to accept the huge costs from smoking. The obvious humane response to this is to try to lower these costs, by providing a substitute for smoking. The opposite strategy, continually increasing the costs until they exceed the benefits, making people so miserable that they quit, is puritanical and cruel.
But isn't nicotine used as an insecticide? But isn't pure nicotine highly toxic? But isn't the nicotine in a pack of cigarettes a lethal dose? Yes, yes, and yes. But so what?
A lot of anti-nicotine advocates try to scare people by saying things that while scientifically accurate, are just designed to confuse. Tobacco plants produce nicotine as a natural insecticide, and this can be concentrated for use as an artificial insecticide. This should not come as a shock. Mmany of the chemicals in plants that we like are part of the plants' defense mechanisms. Pretty much every plant we eat or do anything else with contains natural insecticides. It just happens that this chemical, which sometimes poisons insects, also provides an effect that some people like.
It is also true that a drop of pure nicotine can be deadly, and that if you concentrated the nicotine from a pack of cigarettes (or a can of snuff, or a box of pharmaceutical nicotine products) and put it into your body all at once, it would likely be fatal. But, again, so what? Nicotine users are never exposed to pure nicotine and never take in that much all at once. If you took your typical day's worth of food and stuffed it in your mouth all at once, that would probably kill you too, even though it would be harmless if you took the usual time. This may seem like a silly analogy but it is no more silly than saying that a huge dose of nicotine, delivered all at once, would be deadly. Neither one says anything about the safety of normal use.
Keep in mind the saying from toxicology: "The dose makes the poison." Enough of anything, delivered fast enough, is deadly (including food or water). For many medicines you have on your shelf, ingesting the entire bottle at once would be deadly.
In any case, it is best to go back to the scientific evidence. Long term users of nicotine who do not smoke (ST users) suffer few ill effects from their habits, as we describe above. If nicotine were deadly, we would expect to see a lot of these people die prematurely. We do not see that.
There is no real evidence that anyone who otherwise would not have smoked starts because of ST use. But to the extent that people do switch, the best thing we could do is make sure they have the facts. This is a case where the anti-tobacco literature actually encourages some people to smoke.
Some anti-smokeless-tobacco advocates have realized that they have no legitimate scientific basis for arguing that there are major health impacts associated with smokeless tobacco use. But instead of seeing that as a reason to devote their attention to more dangerous exposures, they just decided to search for other arguments. One such is the "gateway" hypothesis, that using ST leads people to later start smoking.
True or not, this claim is irrelevant to harm reduction, which is aimed at people who already smoke. It makes sense that many people who like to use one tobacco product will like to use another, in particular because they like nicotine. Many people do use one product and then switch to another. This does not mean that if the first product had not existed, they never would never have tried the second. Quite likely they would have tried the second product in the first place. The gateway argument assumes that some people never would have tried cigarettes were it not for ST, which seems improbable in a culture where cigarettes are so common.
In any case, if the gateway claim were true, we would have to eliminate smokeless tobacco entirely to keep it from happening, which would be a terrible option, leaving tobacco users without a good reduced-harm alternative.
Most important, if there is a gateway effect, the harm reduction message is actually the best way to deal with it. The dominant misinformation, that ST is about as unhealthy as smoking, tells ST users, "you might as well smoke". This irresponsible message translates to something along the lines of "if you use nicotine, and you like cigarettes more than ST, then go ahead and smoke". Many people try both products and settle on cigarettes. If people are going to use one product or the other, we'd rather they settle on the safer one, on ST.
Anti-tobacco advocates tend to treat tobacco users as if they are complete idiots, helpless children who cannot make a rational decision and need to be manipulated. We think otherwise. We think that many tobacco users will choose a product that is over 99% less harmful, as soon as someone can break through the propaganda and let them see their true options. Then "the gateway" will be an exit from, rather than an entrance to, smoking.