How effective is nicotine replacement therapy?

Photo of a man at the pharmacy

It is possible to become very dependent on nicotine. That’s why most smokers experience unpleasant withdrawal symptoms if they stop smoking suddenly. Nicotine gum and patches can relieve these symptoms, increasing the likelihood of successfully quitting smoking.

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 to help you successfully quit.


In order to work, nicotine replacement therapy must be used for the prescribed length of time at the recommended dose. The package insert includes this information, and your pharmacist will explain it to you as well.

How can nicotine replacement therapy help?

In nicotine replacement therapy the nicotine in tobacco is replaced by other nicotine products, such as gum or patches. Although the term “nicotine replacement therapy” implies something quite different, nicotine is not replaced by another substance in this type of treatment. The dose is gradually reduced so that the body get used to less nicotine. This continues until you can do without any at all.

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.

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

Nicotine replacement therapy products are only available in pharmacies. But you can buy them without a prescription. The package insert will describe exactly how to use the product. You can also ask your doctor or pharmacist to explain it to you.

The type of nicotine replacement therapy you choose is a matter of personal preference. Any of these products will make it easier to quit.

How much does nicotine replacement therapy cost?

The cost of nicotine replacement therapy depends on the specific products you use and how long they are needed. It generally costs about 150 to 250 euros. But this doesn’t need to be paid all at once since the cost is divided among several packs.

Some smokers are put off by the cost of this treatment. It isn’t due immediately though, and the products are available in small packs intended to be used for about two weeks. And people who manage to stop smoking save money over the long run – much more than the cost of the therapy.

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.

To start out with, you chew eight to twelve pieces of gum, spread out across the day, or more if needed. The dose is gradually reduced over several weeks until you can manage with just one or two pieces of gum per day. It's usually possible to stop using the gum completely after about three to six months.

Nicotine gum is available in 2 and 4 milligram (mg) doses. If you smoked more than 20 to 30 cigarettes per day, you are advised to use the higher dose because that will increase your chances of success.

Nicotine patch

Nicotine patches release nicotine, which is slowly and continuously absorbed into the body through the skin. Three different doses are usually 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.

The treatment takes about three months, during which the dose is gradually reduced by switching to lower-dose packs. The dose and duration of treatment are determined based on how much you used to smoke.


Lozenges release the nicotine when you suck them. It is absorbed into the body through the membranes lining the mouth. Depending on the specific product, it is recommended to take one lozenge every 1 to 2 hours for the first six to twelve weeks after you stop smoking (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. 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 you 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 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 over 130 studies involving nearly 65,000 people. They concluded that nicotine replacement therapy can help people to quit smoking:

  • Without nicotine replacement therapy, around 11 out of 100 people managed to quit smoking.
  • With nicotine replacement therapy, around 17 out of 100 people managed to quit smoking.

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

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

These figures are all averages. The likelihood of successfully quitting is greatest if the nicotine replacement therapy is combined with other strategies, like a course for quitting smoking.

The research also shows 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?

Nicotine replacement therapy is safe. But depending on the type of product used, 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?

Smoking cessation (quitting smoking) programs can help to quit smoking during pregnancy. Research has shown that pregnant women find it easier to stop smoking if they receive professional advice.

Only a small number of studies have looked into whether nicotine replacement therapy helps in pregnancy. No benefit was found.

So medical societies consider nicotine replacement therapy to be a suitable option during pregnancy only if the therapy is supervised by a doctor and other support strategies have been unsuccessful.

Batra A, Kiefer F, Andreas S et al. S3-Leitlinie „Rauchen und Tabakabhängigkeit: Screening, Diagnostik und Behandlung“. AWMF-Registernr.: 076-006. 2021.

Chamberlain C, O'Mara-Eves A, Porter J et al. Psychosocial interventions for supporting women to stop smoking in pregnancy. Cochrane Database Syst Rev 2017; (2): CD001055.

Claire R, Chamberlain C, Davey MA et al. Pharmacological interventions for promoting smoking cessation during pregnancy. Cochrane Database Syst Rev 2020; (3): CD010078.

Hartmann-Boyce J, Chepkin SC, Ye W et al. Nicotine replacement therapy versus control for smoking cessation. Cochrane Database Syst Rev 2018; (5): CD000146.

Lindson N, Chepkin SC, Ye W et al. Different doses, durations and modes of delivery of nicotine replacement therapy for smoking cessation. Cochrane Database Syst Rev 2019; (4): CD013308.

Mills EJ, Wu P, Lockhart I et al. Adverse events associated with nicotine replacement therapy (NRT) for smoking cessation. A systematic review and meta-analysis of one hundred and twenty studies involving 177,390 individuals. Tob Induc Dis 2010; 8(1): 8.

Patnode CD, Henderson JT, Thompson JH et al. 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. 2015.

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 September 7, 2022

Next planned update: 2025


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

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