Nicotine replacement therapy

Photo of a man at the pharmacy

Nicotine is a potentially addictive substance. Most smokers experience unpleasant withdrawal symptoms if they stop smoking suddenly. Nicotine replacement therapy can relieve the symptoms and help people to stay away from cigarettes.

Quitting smoking is usually especially difficult in the first week. The body doesn’t get its usual dose of nicotine, and this can lead to withdrawal symptoms such as restlessness, irritability, feeling down, and a craving for cigarettes. Many people find it harder to concentrate, and are hungrier than usual. Nicotine replacement therapy (NRT) can reduce these withdrawal symptoms.

How does nicotine replacement therapy work?

Even if the term “nicotine replacement therapy” implies something quite different, nicotine is not replaced by another substance in this type of treatment. The body is still provided with nicotine – not for the stimulating effect, but in order to make it easier for people to stop smoking.

Nicotine replacement therapy comes in various forms. Those approved for use in Germany are nicotine gum, patches, lozenges, inhalers and sprays. All of these products provide a smaller and slower dose of nicotine than smoking a cigarette does. They also don’t contain harmful substances found in cigarette smoke, such as tar and carbon monoxide.

Nicotine replacement therapy products are only available in pharmacies. But you can buy them without a prescription. In Germany, statutory health insurers don’t cover the costs of this treatment or medication for quitting smoking.

People who want to use nicotine replacement therapy can either start doing so when they stop smoking, or one to two weeks beforehand.

Some smokers are put off by the costs of this treatment. But people who manage to stop smoking will already start reaping the financial benefits after a few weeks or months, despite having spent money on the NRT products.

Nicotine gum

Nicotine gum needs to be chewed for about 30 minutes in order to release all the nicotine. It is important to chew it slowly, taking breaks between chewing. This allows the nicotine to be gradually released from the gum and enter the body through the membranes lining the inside of the mouth. Nicotine gum comes in various flavors, such as peppermint or fruit.

The initial recommended daily amount is 8 to 12 pieces of gum, spread out across the day. After 4 to 12 weeks, the dose is then gradually reduced until you can manage with just 1 to 2 pieces of gum per day. Eventually you can stop using the gum. This is usually possible after 3 to 6 months.

Nicotine gum is available in 2 and 4 milligram (mg) doses. People who smoke more than 20 cigarettes per day are advised to use the higher dose because that increases their chances of success.

Nicotine patch

Nicotine patches release nicotine, which is slowly and continuously absorbed into the body through the skin. Different doses are available. The patches are placed on the skin after waking up, and left there for 16 to 24 hours. They can be placed on the inner or outer part of the upper arm, on the shoulder or on the hip, for example.

In order to make sure the patch sticks properly, it's important to hold it against your skin for 10 to 20 seconds. The skin should be clean and dry, and not have any cream on it. The patch should also be used on a different area of skin every day. It is advisable to wait several days before putting a patch on the same area of skin again.

The treatment takes about 8 to 10 weeks, during which the dose is gradually reduced. The dose and duration of treatment are determined based on how much the person smokes.


Lozenges release nicotine when you suck them. The nicotine is absorbed into the body through the membranes lining the mouth. During the first six weeks, the recommended daily amount is one lozenge every 1 to 2 hours (about 8 to 12 lozenges per day). After that, the daily amount of lozenges is gradually reduced until you no longer need them.

Nicotine lozenges come in doses of 1 to 4 mg mg. Here, too, the initial dose will depend on how much the person smokes.

Inhalers and sprays

Breathing in nicotine through an inhaler is similar to inhaling when smoking a cigarette. Disposable cartridges or capsules are attached to the mouthpiece of the inhaler. One cartridge contains 15 mg of nicotine, which is enough to "smoke" several times. Depending on how much the person used to smoke, they may use 3 to 6 cartridges per day.  In order to get enough nicotine out of the inhaler, you have to inhale much more frequently over a period of about 10 to 20 minutes. Here, too, people start using the inhaler less and less after three months, until they no longer need it.

The nicotine spray is sprayed into your mouth about once or twice an hour – similar to the rate at which cigarettes are smoked. After six weeks the number of sprays per day is gradually reduced, until you can get by without nicotine. This should usually be possible within about 3 to 6 months.

How effective is nicotine replacement therapy?

There has been a lot of scientific research on nicotine replacement therapy. The study participants used to smoke at least 15 cigarettes per day, or in most cases even more than 20. Nearly all of the participants were offered additional support too, such as professional advice. After 6 to 12 months the researchers looked at whether the participants still smoked, or had started smoking again.

Researchers from the analyzed the results of the studies. They concluded that nicotine replacement therapy can help people to quit smoking:

  • Without nicotine replacement therapy, around 10 out of 100 people managed to quit smoking.
  • With nicotine replacement therapy, around 16 out of 100 people managed to quit smoking.

In other words, nicotine replacement therapy helped an extra 6 out of 100 people to successfully stop smoking.

But several groups of researchers suspect that a number of other studies found that nicotine replacement therapy doesn't work, and that those studies weren't published. If this "publication bias" is taken into account, it is estimated that nicotine replacement therapy only helps about 3 out of 100 people to stop smoking.

The studies also show that nicotine gum and patches hardly affect people's weight. Compared to people who didn't use nicotine replacement therapy, those who did weighed about half a kilogram to one kilogram (about one to two pounds) less on average at the end of treatment. There was no longer a clear difference between the groups after one year, though.

Illustration: How effectively nicotine replacement therapy helps people to quit smoking – as described in the article

Several studies suggest that combining two types of nicotine replacement therapy is somewhat more effective than using just one. For instance, nicotine patches can be combined with lozenges.

What are the possible side effects?

Depending on the type of product used for nicotine replacement therapy, it can have various temporary side effects. If the side effects become too unpleasant, it may be worth trying out a different type of product.

The possible side effects of nicotine gum, lozenges, inhalers and sprays include indigestion and irritated mucous membranes. 11 out of 100 people in studies developed sores in their mouth or throat, and 4 out of 100 people had indigestion. Some occasionally had hiccups too.

Nicotine patches can also irritate the skin: This happened in 13 out of 100 study participants. The patches rarely have other side effects.

There is no need to be concerned about more severe side effects. Although studies have found that nicotine replacement therapy causes heart palpitations in 1 out of 100 people, there is no to suggest that this increases the risk of heart disease.

Can pregnant women use nicotine replacement therapy?

Only a small number of studies have looked into whether nicotine replacement therapy helps in pregnancy. No benefit was found. It also isn't clear how this treatment might affect the health of the unborn child. But it is assumed that nicotine replacement therapy is less harmful than continuing to smoke. Smoking cessation (quitting smoking) programs are an alternative to nicotine replacement therapy. Research has shown that pregnant women find it easier to stop smoking if they receive professional advice.

Chamberlain C, O'Mara-Eves A, Porter J, Coleman T, Perlen SM, Thomas J et al. Psychosocial interventions for supporting women to stop smoking in pregnancy. Cochrane Database Syst Rev 2017; (2): CD001055.

Coleman T, Chamberlain C, Davey MA, Cooper SE, Leonardi-Bee J. Pharmacological interventions for promoting smoking cessation during pregnancy. Cochrane Database Syst Rev 2015; (12): CD010078.

Etter JF, Burri M, Stapleton J. The impact of pharmaceutical company funding on results of randomized trials of nicotine replacement therapy for smoking cessation: a meta-analysis. Addiction 2007; 102(5): 815-822.

Patnode CD, Henderson JT, Thompson JH, Senger CA, Fortmann SP, Whitlock EP. Behavioral Counseling and Pharmacotherapy Interventions for Tobacco Cessation in Adults, Including Pregnant Women: A Review of Reviews for the U.S. Preventive Services Task Force. September 2015. (AHRQ Evidence Syntheses; Volume 134).

Stanley TD, Massey S. Evidence of nicotine replacement's effectiveness dissolves when meta-regression accommodates multiple sources of bias. J Clin Epidemiol 2016; 79: 41-45.

Stead LF, Perera R, Bullen C, Mant D, Hartmann-Boyce J, Cahill K et al. Nicotine replacement therapy for smoking cessation. Cochrane Database Syst Rev 2012; (11): CD000146.

IQWiG health information is written with the aim of helping people understand the advantages and disadvantages of the main treatment options and health care services.

Because IQWiG is a German institute, some of the information provided here is specific to the German health care system. The suitability of any of the described options in an individual case can be determined by talking to a doctor. can provide support for talks with doctors and other medical professionals, but cannot replace them. We do not offer individual consultations.

Our information is based on the results of good-quality studies. It is written by a team of health care professionals, scientists and editors, and reviewed by external experts. You can find a detailed description of how our health information is produced and updated in our methods.

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Updated on August 24, 2017
Next planned update: 2022


Institute for Quality and Efficiency in Health Care (IQWiG, Germany)

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