Nicotine replacement therapy (NRT): evidence on help to quit smoking

In this blog for people wanting to quit smoking, Sarah Chapman shares new Cochrane evidence on the effectiveness of nicotine replacement therapy.

Page last updated 6 February 2023

Take-home points

There is reliable Cochrane evidence that using a combination of two nicotine replacement therapy (NRT) products increases the likelihood of quitting smoking successfully compared to using one type of NRT Using NRT prior to quitting probably improves quit rates versus using it from the quit date only Unwanted effects relate to the type of product, such as skin irritation from patches. The evidence does not indicate that risks are increased when more than one type of NRT is used


People who use a combination of nicotine replacement therapies (NRT) are more likely to successfully quit smoking than those using one type. That’s the headline message backed by high quality evidence, in the Cochrane Review Different doses, durations and modes of delivery of nicotine replacement therapy for smoking cessation (published April 2019).

This is a really important finding both for people buying nicotine replacement products to help them quit and for those commissioning NHS stop smoking services.

What is nicotine replacement therapy (NRT)?

 We already have evidence that nicotine replacement therapy can help smokers to quit, from the earlier Cochrane Review Nicotine replacement therapy versus control for smoking cessation (published May 2018). It does this by replacing the nicotine they are used to getting from tobacco, getting it to the brain through a variety of routes. NRT is available as sprays (into the nose or mouth), inhalers, gum, lozenges, tablets and skin patches. But which way is best?

New evidence about NRT

A team from Cochrane Tobacco Addiction did a systematic review with the aim of answering this question. They looked for all the relevant research studies and found 63 trials involving 41,509 smokers (mostly adults) who wanted to quit. Most smoked at least 15 cigarettes a day at the start.

More is better

They found that people using a nicotine patch together with another type of NRT, such as lozenges, were more likely to quit smoking for six months or more than people using just one type of NRT.

Does the dose matter?

 Using higher dose nicotine gum made successful quitting more likely than lower dose gum (4mg of nicotine versus 2mg). The evidence is less certain on doses of nicotine in skin patches, but higher dose nicotine patches (containing 25mg or 21mg) probably make quitting more likely than lower dose patches (15mg or 14mg).

Starting NRT before quitting may help

This is something we need more evidence to be sure about, but it seems that starting NRT before ‘quit day’, the day on which someone stops smoking, probably improves the chance of success.

Starting NRT before quit day probably increases the chances of quitting

Is NRT safe?

It’s always important to know about the potential harms as well as benefits of any treatment. Most of the studies didn’t look at this! Those that did found that very few people experienced harmful effects of NRT and those mentioned were minor, such as skin irritation with patches. The evidence does not indicate that risks are increased when more than one type of NRT is used. NRT is considered to be safe, but little is known about how different types of NRT compare in terms of harmful effects.

Where does this leave us?

Lead author, Dr Nicola Lindson from the Nuffield Department of Primary Care Health Sciences, University of Oxford, UK said “This high-quality evidence clearly signposts that the most effective way to use NRT is to use a combination of two products at once, a patch and a fast acting form such as gum, nasal spray or lozenge. Quitting this way increases the chances of you stopping smoking altogether.”

Dr Lindson also highlighted the questions that the existing research doesn’t answer, including how long NRT should be used for and whether it makes a difference to successful quitting if smokers pay for NRT or have it provided for free.

This leaves plenty of work for researchers to do, while producers of prescribing guidelines will need to consider the findings of this review. For smokers wanting to quit, it’s good to know that this review has some high-quality evidence to inform their decisions about using NRT to help them.

Join the conversation on Twitter with @CochraneUK @CochraneTAG @SarahChapman30 or leave a comment on the blog. Please note, we cannot give specific medical advice and do not publish comments that link to individual pages requesting donations or to commercial sites, or appear to endorse commercial products. We welcome diverse views and encourage discussion but we ask that comments are respectful and reserve the right to not publish any we consider offensive. Cochrane UK does not fact check – or endorse – readers’ comments, including any treatments mentioned.

References (pdf)

Sarah Chapman has nothing to disclose.


Nicotine replacement therapy (NRT): evidence on help to quit smoking by Sarah Chapman

is licensed under a Creative Commons Attribution-NoDerivatives 4.0 International

1 Comments on this post

  1. I have successfully quit after 37 years. I used a patch for one week, then lozenges for another three years, during which I learned to live without cigarettes. This included drinking alcohol regularly without any cigarettes. None.
    In the beginning I used a half of one NiQuitin 21mg per day pressed on firmly for one minute, reduced to one third of that at night for sleep (one sixth of a patch). Daily, after my evening meal I showered, but used no shampoo or underarm deodorant, they both hinder the ‘sweating out’ of harmful smoking metabolites and this is essential to restore balance. Soap only on scalp, I’m afraid.
    After 7 days of this routine, I woke up on day 8 and used lozenges only. They were excellent, they did their job and I loved having them around for the next three years.
    I finally gave up the lozenges one month ago, and I’ve never been happier. I simply stopped dead, used the cleansing routine again (showers, no shampoo) and used sugar free mints. This had been an overwhelming success for me, and I really felt I had to share, if it can help even one person.
    I had previously tried many times to use NRT, and my methods are the result of much trial and error, but this works. I am male, but I believe that women should start NRT at the first sign of menstruation, in order that they should rid the body of any harmful metabolites in the old uterine lining.
    OK thanks for your time.

    Matt F / Reply

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