Nicotine Replacement Therapy

Nicotine replacement therapy, usually shortened to NRT, delivers nicotine without the smoke so that cravings and withdrawal are easier to handle while a person stops smoking. Cochrane's main review of the evidence, last updated with trials to July 2017, pooled 133 trials with 64,640 participants and found a risk ratio of 1.55 (95% confidence interval 1.49 to 1.61) for quitting for at least six months with any form of NRT, compared with placebo or no NRT. A risk ratio is the quit rate with treatment divided by the quit rate in the comparison group, so 1.55 means the treated group did better by that multiple. This page covers the products, the combination approach, the safety record and who should speak to a clinician first. It sits alongside the broader quit methods compared page.

The five forms

The CDC states that five NRTs are approved by the US Food and Drug Administration for quitting smoking: the patch, gum, lozenge, oral inhaler and nasal spray. Nicotine is the active ingredient in all of them. Patches, gum and lozenges are the most common and can be bought without a prescription. The CDC adds that NRT supplies nicotine without the hundreds of harmful chemicals in cigarette smoke, and that even with NRT a person will likely still have some discomfort and urges to smoke.

The patch releases nicotine slowly through the skin. Gum, lozenges, sprays and inhalers deliver it faster, though less rapidly than smoking does, according to Cochrane. That difference matters for the combination approach described below. Why nicotine has such a strong grip in the first place is covered in how nicotine dependence works.

What Cochrane found on effectiveness

Cochrane rated the evidence for NRT as high quality, meaning further research is very unlikely to change the conclusion. Its authors summarised the effect as an increase in the chance of quitting of 50% to 60%, and found that this held with or without additional counselling. Results for each product, as pooled risk ratios against control, were:

nicotine gum: 1.49 (95% interval 1.40 to 1.60; 56 trials)
nicotine patch: 1.64 (1.53 to 1.75; 51 trials)
oral tablets and lozenges: 1.52 (1.32 to 1.74; 8 trials)
nicotine inhaler: 1.90 (1.36 to 2.67; 4 trials, 976 participants)
nicotine nasal spray: 2.02 (1.49 to 2.73; 4 trials, 887 participants)

The inhaler and spray figures look larger, but they rest on only four small trials each, and the intervals are wide. The 2023 Cochrane network meta-analysis, which combined direct and indirect comparisons, reported odds ratios of 1.37 for the patch alone and 1.41 for fast-acting NRT alone against control, both with high-certainty evidence.

Combining short-acting and long-acting products

A separate Cochrane review of 68 studies and 43,327 participants (evidence to April 2022) looked at how NRT is used. It found high-certainty evidence that a patch plus a fast-acting form, such as gum or lozenge, led to higher long-term quit rates than a single form (risk ratio 1.27, 95% interval 1.17 to 1.37; 16 studies, 12,169 participants). It also found high-certainty evidence that a fast-acting form and a patch gave similar quit rates when used on their own (risk ratio 0.90, 0.77 to 1.05). The CDC makes the same point in practical terms: a long-acting patch used at the same time as a short-acting product such as a lozenge or gum can decrease withdrawal even more.

The same review found moderate-certainty evidence that starting NRT before the quit day may improve quit rates compared with starting on quit day (risk ratio 1.25, 1.08 to 1.44; nine studies), though the authors said more research is needed. Cochrane also noted that evidence on how long to use NRT, and on tapering, was limited. Dose and duration are decisions for the product label and a pharmacist or clinician, who can account for how much a person smokes and their health.

Safety notes

Cochrane described side effects as related to the product: skin irritation from patches, and irritation inside the mouth from gum and tablets. The CDC lists skin redness, itching or burning, headache, and sleep disturbance with vivid dreams as possible effects of the patch. Cochrane found no evidence that NRT increases the risk of heart attacks. It did find a higher odds of chest pain or palpitations with NRT (odds ratio 1.88, 95% interval 1.37 to 2.57; 15 trials), but said these symptoms were rare in both groups and that serious adverse events were extremely rare.

The 2023 review on dose and delivery found that most studies did not measure safety well, so it rated the evidence on comparative safety as low or very low certainty, while pointing to large studies in a separate review that show high-certainty evidence NRT is safe for quitting. In one study, more people stopped nasal spray than patches because of side effects (risk ratio 3.47), but that result was very low certainty.

Who should ask a clinician or pharmacist first

The CDC's page on the patch says to talk to a doctor or other healthcare provider before starting if any of these apply: a heart attack in the last two weeks, a serious heart rhythm problem, serious or worsening angina, an allergy to adhesive tape or serious skin problems such as psoriasis or eczema, being pregnant or breastfeeding, or being under 18. Its general guidance on the medicines says people who are pregnant, breastfeeding or younger than 18 should not use them without talking to a doctor.

The NHS takes a more specific line on pregnancy, describing NRTs as licensed stop smoking products that are safe to use in pregnancy if support is needed, and still advising people to speak to a healthcare professional first. The two bodies word this differently, which is a good reason to take the question to a pharmacist, midwife or doctor. The product label and a pharmacist set the dose; this site does not.

What to do after a slip is covered on the relapse and slips page, and the symptoms NRT aims to ease are mapped on the withdrawal timeline.

Frequently asked questions

Is nicotine replacement therapy safe?

Cochrane found no evidence that NRT increases heart attack risk and described serious adverse events as extremely rare. Chest pain and palpitations were more common with NRT but rare in both groups. People with heart conditions should ask a clinician first.

Can you use two kinds of NRT at once?

Yes, and Cochrane found it works better than one form alone, with a risk ratio of 1.27. The usual pairing is a patch with a fast-acting form such as gum or lozenge. The label and a pharmacist can say how to combine them.

Do you need a prescription for nicotine patches?

The CDC says patches, gum and lozenges can be bought without a prescription in the US. Cochrane also noted that NRT does not need to be prescribed by a doctor. Rules differ between countries, so a pharmacist can confirm locally.

The short version

Cochrane's high-quality evidence puts any form of NRT at a risk ratio of 1.55 for quitting at six months or longer, and a patch plus a fast-acting form does better than one product. Side effects are mostly local irritation. Anyone with heart disease, who is pregnant or breastfeeding, or who takes other medicines should check with a pharmacist or clinician before starting.