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Cancer Risk and Prevention

Nicotine Replacement Therapy to Help You Quit Tobacco

Nicotine is the main addictive substance in tobacco. When a person uses tobacco, many parts of the body get used to having nicotine in them. When a person quits tobacco, they also quit nicotine and will likely have withdrawal symptoms from it. This is because the body has to get used to not having nicotine.

The nicotine in tobacco leads to actual physical dependence. This can cause unpleasant withdrawal symptoms when a person tries to quit. Nicotine replacement therapy (NRT) gives you nicotine – in the form of gum, patches, sprays, inhalers, or lozenges – but not the other harmful chemicals in tobacco. NRT can help relieve some of the physical withdrawal symptoms so that you can focus on the psychological (emotional) aspects of quitting.

Many studies have shown using NRT can nearly double the chances of quitting smoking. It hasn’t been studied as much for quitting smokeless tobacco, but the NRT lozenges may help.

People who smoke and are significantly dependent on nicotine should consider nicotine replacement or drug therapy to help them quit. Signs of severe nicotine dependence include:

  • Smoking more than 1 pack a day
  • Smoking within 5 minutes of waking up
  • Smoking even while sick
  • Waking up at night to smoke
  • Smoking to ease symptoms of withdrawal

The more of these that apply, the more serious the nicotine dependence.

How does nicotine replacement therapy work?

Nicotine replacement therapy (NRT) can help with the difficult withdrawal symptoms and cravings that most people say is their only reason for not giving up tobacco. Using NRT reduces those symptoms.

Many people can quit tobacco without using NRT, but most of those who attempt quitting do not succeed on the first try. In fact, people trying to quit usually need many tries before they’re able to quit for good. Most people who try to quit on their own go back to smoking within the first month of quitting – often because of the withdrawal symptoms. But the good news is that many do succeed. In fact, there are now more people who formerly smoked than people who currently smoke!

Together with counseling or other support, NRT may help increase the number of smokeless tobacco users who quit, too.

You can start using nicotine replacement therapy (NRT) as soon as you throw away your tobacco. You don’t need to wait a certain length of time to put on the patch or start using the gum, lozenge, nasal spray, or inhaler. Double-check this information with the instructions on your chosen method of nicotine replacement, but in general there’s no need to wait to start using NRT.

Getting the most from nicotine replacement therapy

Nicotine replacement therapy (NRT) only deals with the physical dependence. It’s not meant to be the only thing you use to help you quit smoking. You’ll need other methods that help with the psychological (emotional and mental) part of tobacco, such as a quit program. Use these support systems during treatment with NRT and for at least a few months after you quit. Studies have shown that this approach – pairing NRT with a program that helps to change behavior – can improve your chances of quitting and staying quit compared to approaches that use only one method.

The best time to start NRT is when you first quit. Often people first try to quit tobacco on their own then decide to try NRT a day or more into quitting. This does not give you the greatest chance of success, but don’t let this discourage you. There are many options for quitting and staying quit. Just remember that it often takes many tries.

The Food and Drug Administration (FDA) has approved the NRT products discussed here as effective aids for helping people quit smoking. None of these products has been FDA-approved specifically to help people quit smokeless tobacco. Still, studies are being done, and some have shown the lozenge form may help.

Who should not use nicotine replacement therapy?

The US Agency for Healthcare Research and Quality states that nicotine replacement therapy (NRT) is safe for all adults who want to quit smoking except pregnant women and teens. Still, it’s best to discuss NRT use with your health care provider before starting it. You may have medical problems that should be considered. When deciding whether to use NRT, the benefits of quitting tobacco must outweigh the potential health risks of NRT for each person.

People who are still smoking or using any other form of tobacco should not use NRT. The companies that make NRT products warn that you should not use them if you’re still using tobacco, and the FDA has not approved them to be used in this way. Get the advice of a health care provider if you want to use NRT while continuing to smoke or chew.

NRT has not yet been proven to help people who smoke fewer than 10 cigarettes a day. But many tobacco treatment centers do use NRT for people who are "light smokers." Talk with your health care provider about a lower dose of NRT if you smoke less than that but feel you need nicotine replacement.

Types of nicotine replacement therapy

The US Food and Drug Administration (FDA) has approved 5 forms of nicotine replacement therapy (NRT):

  • Patch
  • Gum
  • Nasal spray
  • Inhalers
  • Lozenges

Note that the patch, gum, and lozenge can be purchased over the counter, while the nasal spray and inhaler require a prescription.

The most important thing to do with any form of NRT is read and follow the package instructions very carefully.

Nicotine patches (transdermal nicotine systems)

Patches can be bought with or without a prescription.

Patches give a measured dose of nicotine through the skin. You’re weaned off nicotine by switching to lower-dose patches over a course of weeks.

Many different types and strengths of patches are available, including 16-hour and 24-hour patches. Which patch you should use depends on how many cigarettes you smoke each day. Package instructions tell you how to use them, and list special considerations and possible side effects.

How to use nicotine patches: Depending on body size and smoking habits, most people who smoke should start using a full-strength patch (15-22 mg of nicotine) daily for several weeks, and then use a weaker patch (5-14 mg of nicotine) for another several weeks. The patch is changed every day. It should be put on in the morning on a clean, dry area of the skin without much hair. It should be placed below the neck and above the waist – for instance, on the upper arm or chest. The FDA has approved using the patch for a total of 3 to 5 months, but using it longer is better than going back to smoking.

Possible side effects of the nicotine patch include:

  • Skin irritation (redness and itching)
  • Dizziness
  • Racing heartbeat
  • Sleep problems or unusual dreams (more common with the 24-hour patch)
  • Headache
  • Nausea
  • Muscle aches and stiffness

No one has all of the side effects, and some people have none. Some side effects, such as racing heart, may mean the dose of nicotine is too high for you. Stop using the patch and talk to your health care provider if this happens. You could also have nicotine withdrawal symptoms if your NRT dose is too low.

What to do about side effects

  • Try a different brand of patch if your skin becomes irritated.
  • Reduce the amount of nicotine by using a lower-dose patch.
  • Sleep problems may go away in 3 or 4 days. If not, and you’re using a 24-hour patch, try switching to a 16-hour patch.
  • Stop using the patch and try a different form of NRT.

Nicotine gum (nicotine polacrilex)

Nicotine gum can be bought without a prescription.

Nicotine gum is a fast-acting form of replacement. Nicotine is taken in through the mucous membrane of the mouth. You can buy it over the counter (without a prescription). It comes in 2 mg and 4 mg strengths.

In choosing your dose, think about whether you

  • Smoke 25 or more cigarettes per day
  • Smoke within 30 minutes of waking up
  • Have trouble not smoking in restricted areas

If any of these describe you, you may need to start with the higher 4mg gum dose.

How to use nicotine gum

For best results, follow the instructions in the package. Nicotine gum is not meant to be used like regular gum. Chew the gum slowly until you get a peppery taste or tingle. Then tuck it inside your cheek until the taste fades. Chew it to get the peppery taste back, and hold it again. Do this off and on for 20 to 30 minutes. Food and drink can affect how well the nicotine is absorbed, so don’t eat or drink for at least 15 minutes before and during gum use. This is important because many people misuse the nicotine gum and chew it like regular gum instead of how it should be used.

An advantage of nicotine gum is that it allows you to control the amount of nicotine you get. The gum can be used as needed or on a fixed schedule during the day. The most recent research has shown that scheduled dosing works better. A schedule of 1 to 2 pieces per hour is common. On the other hand, with an as-needed schedule, you can use it when you need it most – when you have cravings.

Chew no more than 24 pieces of gum in one day. Nicotine gum is usually recommended for 6 to 12 weeks, with the maximum being 6 months. Tapering down the amount of gum you use as you approach 3 months may help you stop using it. But it is better to keep using the gum rather than starting to smoke again.

Possible side effects of nicotine gum include:

  • Bad taste
  • Throat irritation
  • Mouth sores
  • Hiccups
  • Nausea
  • Jaw discomfort
  • Racing heartbeat

The gum can also stick to and damage dentures and dental work.

Stomach and jaw discomfort are usually caused by improper use of the gum, such as swallowing the nicotine or chewing too fast. No one has all of the side effects, and some people have none. If your heart is racing or beating irregularly, stop using the gum and talk to your health care provider. You could also have nicotine withdrawal symptoms if your NRT dose is too low.

Nicotine nasal spray

Nicotine nasal spray is only available by prescription.

The nasal spray delivers nicotine to the bloodstream rapidly because it’s absorbed through the nose. It relieves withdrawal symptoms very quickly and lets you control your nicotine cravings.

How to use nicotine nasal spray

Most people are told to use 1 to 2 doses per hour. (1 dose = 2 sprays, 1 in each nostril.) At least 8 doses (16 sprays) each day may be needed when you first start, but use as directed by your health care provider. You should not use more than 40 doses (80 sprays) per day. Instructions can vary. Talk to your provider about the plan that’s best for you.

The FDA recommends that the spray be prescribed for 3-month periods and that it not be used for longer than 6 months.

Possible side effects of nicotine spray

The most common side effects of the spray get better in about 1 to 2 weeks and can include:

  • Nasal irritation
  • Runny nose
  • Watery eyes
  • Sneezing
  • Throat irritation
  • Coughing

Other side effects are related to nicotine:

  • Racing heart
  • Nervousness
  • Headache

No one has all of the side effects, and some people have none. Some side effects, such as racing heart, may occur because you’ve gotten too much nicotine. Stop using the spray to see if the feelings get better and talk to your health care provider if this happens. You may need to use it less often. You could also have nicotine withdrawal symptoms if your NRT dose is too low.

If you have asthma, allergies, nasal polyps, or sinus problems, your provider may suggest another form of NRT.

Special note: This form of NRT poses a more serious risk to small children and pets because the empty bottles of nasal spray contain enough nicotine to harm them. Do not get the liquid on your skin. If there’s any skin contact, rinse thoroughly with plain water right away. If a bottle breaks or liquid leaks out, put on plastic or rubber gloves to clean it up. Call Poison Control and get emergency help if there’s any question of overdose.

Nicotine inhalers

Inhalers are available only by prescription.

The nicotine inhaler is a thin plastic tube with a nicotine cartridge inside. Unlike other inhalers, which deliver most of the medicine to the lungs, the nicotine inhaler delivers most of the nicotine vapor to the mouth and throat where it’s absorbed into the bloodstream.

Nicotine inhalers are the FDA-approved nicotine replacement method that’s most like smoking a cigarette, which some people trying to quit find helpful. They are not the same as electronic cigarettes, which are not approved by the FDA to help people quit smoking. At this time, inhalers are the most expensive form of NRT available.

How to use the nicotine oral inhaler

You puff on the inhaler and the cartridge sends a pure nicotine vapor into your mouth. You may use up the cartridge all at once over about 20 minutes, or puff on it only a few minutes at a time. The recommended dose is between 4 and 20 cartridges a day, slowly tapering off over 6 months.

Possible side effects of the nicotine inhaler

The most common side effects, especially when first using the inhaler, include:

  • Coughing
  • Mouth and/or throat irritation
  • Runny nose
  • Upset stomach

Other side effects are related to nicotine:

  • Racing heart
  • Nervousness
  • Headache

No one has all of the side effects, and some people have none. Some side effects, such as racing heart, may occur because you’ve gotten too much nicotine. Stop using the inhaler to see if the feelings get better and talk to your health care provider if this happens. You may need to use it less often. You could also have nicotine withdrawal symptoms if your NRT dose is too low.

Special note: This form of NRT poses an extra risk to small children and pets because the used cartridges still have enough nicotine in them to cause harm if it gets on skin or mucous membranes (for instance, if licked or touched to the eyes, mouth, or other mucous membrane). Be sure to store and dispose of the cartridges away from children and pets. Call Poison Control and get emergency help if there’s any question of overdose.

Nicotine lozenges

Nicotine lozenges can be bought without a prescription.

The lozenge is available in 2 strengths: 2 mg and 4 mg. The needed dose should be based on how long after waking up a person normally has their first cigarette. So, if you smoke your first cigarette within 30 minutes of waking up, use 4 mg nicotine lozenges. If you smoke your first cigarette more than 30 minutes after waking up, use 2 mg-nicotine lozenges. Some people who are using NRT prefer the lozenge to the gum because its use is less conspicuous.

How to use nicotine lozenges

The recommended dose is 1 lozenge every 1 to 2 hours for 6 weeks, then 1 lozenge every 2 to 4 hours for weeks 7 to 9, and finally, 1 lozenge every 4 to 8 hours for weeks 10 to 12. The lozenge makers also recommend:

  • Do not eat or drink for at least 15 minutes before using a lozenge or while using a lozenge. (Some drinks can reduce how well the lozenge works.)
  • Do not use more than 1 lozenge at a time and do not use one right after another.
  • Suck on the lozenge until it is fully dissolved, about 20 to 30 minutes. Move it from side to side in your mouth. Do not bite or chew it like a hard candy, and don’t swallow it. The nicotine absorbs through the mucous membranes of the mouth.
  • Do not use more than 5 lozenges in 6 hours, or more than 20 lozenges per day.
  • Stop using the lozenge after 12 weeks. If you still feel you need to use the lozenge, talk to your doctor.

Possible side effects of the nicotine lozenge

  • Nausea
  • Hiccups
  • Sore throat
  • Coughing
  • Heartburn
  • Headache
  • Gas
  • Trouble sleeping
  • Racing heart

Choosing and using the right nicotine replacement therapy for you

No one type of nicotine replacement therapy (NRT) - by itself or in combination - is necessarily any better than another. When choosing the type of NRT you will use, think about which method will best fit your lifestyle and pattern of smoking or using smokeless tobacco. For example, do you want/need something in your mouth or something to keep your hands busy? Are you looking for once-a-day convenience? How urgent are your cravings for nicotine?

Here are some important points to think about as you decide:

  • Nicotine gums, lozenges, and inhalers are substitutes you can put into your mouth that let you control your dosage to help keep cravings under better control.
  • Nicotine gums and lozenges are generally sugar-free, but if you are diabetic and have any doubts, check with the manufacturer.
  • Nicotine nasal spray works very quickly when you need it.
  • Nicotine inhalers allow you to mimic the use of cigarettes by puffing and holding the inhaler. It also works very quickly.
  • Nicotine patches are convenient and only have to be put on once a day.
  • Both inhalers and nasal sprays require a doctor’s prescription.
  • Some people may not be able to use patches, inhalers, or nasal sprays because of allergies or other conditions.
  • Nicotine gum may stick to dentures or dental work making it hard to chew before “parking.”

Whatever type you use, take your NRT at the recommended dose. NRT is not recommended for long-term use, but if it's needed to prevent relapse, continuing to use NRT is preferable than returning to smoking.

If you use a different dose or stop taking it too soon, NRT can’t be expected to work like it should. If you smoke very heavily very lightly, or are a smokeless tobacco user, talk with your health care provider about how to get the NRT dose that best fits your needs.

What is light, average, and heavy smoking?

Most nicotine replacement therapy (NRT) products recommendations are based on how much you smoke. But there’s no formal category in any textbook or group that defines how much smoking is considered light, average, or heavy smoking.

These are general guidelines:

  • Light smoking: Fewer than 10 cigarettes per day
  • Heavy smoking: A pack a day or more
  • Average smoking falls in between.

How do I know what NRT dose to use based on my smokeless tobacco use?

NRT products are supposed to roughly match the amount of nicotine you typically took in through tobacco. It can be more of a challenge to get the dose right for smokeless tobacco users, since NRT products are labeled for people who smoke.

Certain types of NRT may help more than others. If you look at the way the tobacco is used, nicotine gum and lozenges are most like using smokeless tobacco. They also let you control your dose to help keep nicotine cravings down. To avoid withdrawal symptoms, you want to aim for a nicotine dose fairly close to what you got from snuff or tobacco use.

These are general guidelines:

  • A heavy user is a person who uses more than 3 cans of snuff or 3 pouches of tobacco a week, and would typically use the higher doses of NRT (the dose for people who smoke heavily).
  • Those who use 2 to 3 cans or pouches per week would usually try the moderate doses.
  • Those who use less than 2 would start with the lowest doses of NRT.

If you’ve decided to try NRT, discuss your dose with a health care provider before you quit tobacco.

Combining the patch and other nicotine replacement products

Using the nicotine patch along with shorter-acting products, like the gum, lozenge, nasal spray, or inhaler, is another method of NRT. The idea is to get a steady dose of nicotine with the patch and then use one of the shorter-acting products when you have strong cravings. In general, people who have smoked heavily do better with this combination approach. If you’re thinking about using more than one NRT product, be sure to talk to your health care provider first.

High-dose nicotine replacement therapy for people who smoke heavily

For people who have been smoking heavily, Another option is to use NRT at a higher than usual dose based on the amount of nicotine that they’ve been getting from cigarettes. At this time, not much is known about this option. High-dose NRT should be considered only with a health care provider’s guidance and close supervision.

Can you get too much nicotine from NRT?

Nicotine overdose is rare, but possible. Nicotine replacement therapy (NRT) products are labeled to match the amount of nicotine you get from NRT to the amount you got from tobacco. If used this way, you should get a nicotine dose fairly close to what you’ve been getting. You don’t want to get more than that, because higher doses of nicotine can cause harm. To avoid this, follow dosing instructions carefully. Also, don’t use heat (like a heating pad or heat lamp) on the skin near your nicotine patch – you could absorb more nicotine due to the increased blood supply.

Nicotine absorbs through the skin and mucous membranes, so you must store and dispose of your NRT safely. Nicotine overdose can be fatal, but this is rare and requires taking in very high doses of nicotine. Overdose is more of a problem in children and pets because of their smaller size. Keep NRT and used gum, patches, empty cartridges, bottles, etc., safely away from children and pets. Never drop them on the street or in open trash cans where kids and animals can reach them.

Symptoms of nicotine overdose

Here are some symptoms of too much nicotine:

  • Headache
  • Nausea and vomiting
  • Belly pain
  • Diarrhea
  • Agitation, restlessness
  • Fast or irregular heartbeat
  • Cold sweat
  • Pale skin and mouth
  • Weakness
  • Tremors (shaking)
  • Confusion
  • Disturbed vision and hearing
  • Weakness
  • High blood pressure, which then drops
  • Dizziness or faintness due to low blood pressure
  • Seizures
  • Fast breathing in early poisoning, breathing may stop later

Call Poison Control and get emergency help if you suspect an overdose. If you’re taking NRT as prescribed and are still having mild symptoms such as headache, vomiting, diarrhea, or sweating, lower your dose and talk to your health care provider.

Does nicotine cause cancer?

No, nicotine has not been found to cause cancer. While nicotine is the addictive substance in tobacco, it is other compounds in tobacco that can cause cancer. Using NRT to quit tobacco does not increase your risk of cancer – in fact, it can help lower your risk if it helps you stop using tobacco.

Stopping nicotine replacement therapy

Nicotine replacement therapy (NRT) is meant to be used for a limited period of time. Use should be tapered down before NRT is stopped. Studies to date have not shown that extending NRT use longer than the recommended time greatly impacts quit success. However, long-term NRT use is still preferable to smoking.

Research is still being done to refine the use of NRT. If you feel that you need NRT for a different length of time than is recommended, it’s best to discuss this with your health care provider.

Long-term nicotine replacement therapy dependence

Nicotine replacement therapy (NRT) has the potential for long-term dependence. Nicotine is addictive, and people can transfer their dependence from tobacco to the NRT.

Use NRT only as long as you need it, as prescribed by your health care provider. Talk to your provider if you’re having trouble stopping NRT.

The American Cancer Society medical and editorial content team

Our team is made up of doctors and oncology certified nurses with deep knowledge of cancer care as well as journalists, editors, and translators with extensive experience in medical writing.

This content has been developed by the American Cancer Society in collaboration with the Smoking Cessation Leadership Center to help people who want to learn about quitting tobacco. 

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Last Revised: August 2, 2021

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