Alternative nicotine products: how to read the claims

The patient arrives with phone in hand and shows an article: a new product "reduces almost all toxic substances" compared with cigarettes. He wants to know if he can switch. The question is legitimate, and the answer does not fit into a yes or a no. It depends on four things the headline does not say: compared with what, measured how, for how long and funded by whom.

This text is a critical reading guide for claims about categories of alternative nicotine products: electronic cigarette, heated tobacco and smokeless tobacco. It does not recommend any product. The choice of treatment for those who want to quit is in the text on tobacco cessation at every visit, and the general reasoning of harm reduction is in the text on harm reduction beyond all or nothing.

Key points

• Fewer toxic substances measured is not the same as less disease demonstrated.
• Every promise must state the comparator: cigarettes, abstinence or another treatment.
• The heated tobacco studies were all funded by the tobacco industry and none measured cessation.
• Dual use, smoking and using the product at the same time, is the main trap: cardiovascular risk may remain the same as for those who only smoke.
• Independent reviews show that the nicotine electronic cigarette increases cessation in trials, with follow-up still too short for disease.
• To the patient, the honest answer separates what is known about exposure from what is not yet known about disease.

Summary

• What a product promise usually claims
• Compared with what: cigarettes, abstinence or nothing
• Measured how: emissions, biomarkers or disease
• For how long and in whom: the problem of short follow-up
• Who funded it: how to recognize and weigh the conflict of interest
• Dual use: when adding products does not reduce risk
• What independent reviews show about cessation
• How to answer the patient who asks "is this less bad?"
• Frequently asked questions
• Final checklist

What a product promise usually claims

Claims about alternative nicotine products usually fall into three families. The first speaks of emission: the aerosol has less of certain substances than cigarette smoke. The second speaks of exposure: those who use the product have less of these substances in blood, urine or exhaled air. The third, rarer and stronger, speaks of disease: those who use the product get sick or die less. Each family requires a different type of evidence, and the most common mistake is to accept the first as if it were the third.

Behind the four gaps is an old idea: an intermediate marker only counts when it has already been shown that changing it changes the disease. This criterion, and the history of "reduced exposure" products that did not keep the promise, are in the text on surrogate outcomes and their limits. Here it becomes a practical filter for product promises.

There is also a heuristic component. A word like "natural", "clean" or "smoke-free" activates an impression of safety before any number. It is the same shortcut discussed in the text on when heuristics help and when they get in the way. Recognizing the shortcut is the first step to asking for the right evidence.

In practice, it is worth rewriting any promise as a sentence with four gaps: "in people like X, compared with Y, the product changed measure Z over time T, in a study paid for by W". If one of the gaps cannot be filled, the promise is not yet clinical information. The general guide of critical reading in three questions applies here without adaptation.

Compared with what: cigarettes, abstinence or nothing

Every reduction is relative to something. "Less toxic" almost always means less toxic than continuing to smoke. For those who smoke and will not quit another way, that is the relevant comparison. For those who never smoked, or for those who have already quit, the relevant comparison is with using nothing, and then the same product represents more exposure, not less.

The Cochrane review on heated tobacco shows how the comparator changes the conclusion. Compared with those who kept smoking, those who switched to heated tobacco had lower levels of a nitrosamine metabolite in urine, with a mean difference on the logarithmic scale of minus 0.81, across 10 studies and 1959 participants (Tattan-Birch and colleagues, 2022). Compared with those who tried to go without any tobacco at all, the same metabolite was higher in the heated tobacco group, with a difference of 0.50 on the same scale, across five studies and 382 participants (Tattan-Birch and colleagues, 2022). The same product is "less" and "more", depending on the question.

The National Academies report on e-cigarettes recommended that clinical and epidemiological studies use three comparison groups: people who keep smoking, people who try to quit with other evidence-based treatments, and people who use no tobacco product at all (National Academies of Sciences, Engineering, and Medicine, 2018). A promise that shows only the first comparator answers just one question.

Measured as: emissions, biomarkers or disease

The distance between measuring a substance in the aerosol and demonstrating less disease is long. In between are biomarkers of exposure, which show how much of the substance entered the body, and biomarkers of potential harm, which show some biological effect, such as inflammation or oxidative stress. Neither is disease. A biomarker only substitutes for the clinical outcome when it has already been shown that changing it changes the outcome, reasoning similar to knowing when the test does not change management.

Completely switching from cigarettes to a combustion-free product reduces exposure to many toxic substances, but that, by itself, does not demonstrate less disease. The difference between what a biomarker of exposure and a biomarker of harm can prove is explained in the text on biomarkers of exposure and of harm. What matters here is applying that difference to each promise.

Data on biomarkers of potential harm in those who switched completely point to reductions, but they come mostly from short confinement studies or non-randomized comparisons, with very little information on those who quit everything (Hartmann-Boyce and colleagues, 2023). Two authors of that analysis declare ties to a pharmaceutical company or to a manufacturer of nicotine replacement.

The table below summarizes what to ask when faced with each type of claim.

Type of claim	Critical reading question	Warning sign	What evidence to ask for
"It emits fewer toxic substances"	Measured in a machine or in people? Under what conditions of use?	Only laboratory data, with the manufacturer's protocol	Biomarkers of exposure in real users
"Users have fewer toxins in the body"	Compared with smoking, with quitting or with never using?	Single comparator, chosen by the author	The three comparators, with exclusive use verified
"It improves health markers"	Has the marker already been validated as a substitute for disease?	Follow-up of weeks, markers chosen afterwards	Clinical outcomes or validated markers, with long follow-up
"It reduces the risk of disease"	Cohort or trial? How long? How many events?	Few events, wide confidence interval, former smokers in the reference group	Large and long cohorts, with adjustment for prior smoking
"It helps to quit smoking"	Abstinence confirmed after six months or more?	Reduction outcome, not abstinence	Trials with validated abstinence and an active comparator
"It is safe"	Safe for whom, compared with what, for how long?	Absence of events treated as proof of safety	Long follow-up and surveillance of rare events

For how long and in whom: the problem of short follow-up

Diseases caused by tobacco take decades to appear. A study of weeks can show a change in exposure, but it cannot show a change in cancer or chronic lung disease. In the Cochrane review on heated tobacco, the median follow-up of the 11 trials was 13 weeks (Tattan-Birch and colleagues, 2022). For adverse events, the review found no clear difference between those who switched to heated tobacco and those who kept smoking, with a relative risk of 1.03 and an interval of 0.92 to 1.15, limited by imprecision and risk of bias (Tattan-Birch and colleagues, 2022). Absence of difference at 13 weeks is not absence of harm at 30 years.

The most cited cohort on e-cigarettes and cardiovascular disease followed 24027 adults for at most four years and recorded 1487 cardiovascular events (Berlowitz and colleagues, 2022). Those who used only e-cigarettes had a risk that did not differ from that of those who used nothing, with a hazard ratio of 1.00 and an interval of 0.69 to 1.45 (Berlowitz and colleagues, 2022). The authors themselves point to the small number of events among exclusive users, self-reported and non-adjudicated outcomes, short follow-up for a progressive disease and a reference group that includes former smokers (Berlowitz and colleagues, 2022). The wide interval is compatible both with no difference and with increased risk.

"In whom" matters as much as "for how long". An independent umbrella review gathered 400 publications and found strong evidence that young non-smokers who use e-cigarettes are about three times more likely to start smoking than those who do not, based on 25 longitudinal studies (Banks and colleagues, 2023). The same review concluded that the product may bring benefit to people who smoke and use it to stop completely and quickly, but that it may be harmful to non-smokers, children, adolescents and young adults (Banks and colleagues, 2023). A result in adults who smoke heavily does not transfer to an adolescent who has never smoked.

Products also change faster than studies do. The umbrella review noted that the products assessed in a study do not always reflect those available today and that, for this reason, long-term data are lacking (Banks and colleagues, 2023). Smokeless tobacco, which has existed for much longer, shows what long-term evidence can reveal: a meta-analysis of 80 observational studies found a relative risk of 1.38 for cancer mortality and 1.17 for cancer incidence among users (Htay and colleagues, 2025). The associations appeared in head and neck, oral, esophageal, stomach and pancreatic cancer, with important heterogeneity between studies (Htay and colleagues, 2025). Smokeless did not mean cancer-free.

Who funded it: how to recognize and weigh conflict of interest

Funding does not automatically invalidate a study, but it changes how much one should trust it without replication. When the manufacturer pays for the study, chooses the comparator, defines the outcomes and writes the text, each choice deserves to be checked. Judging a study only by the result it brought is also a mistake, described in the text on retrospective bias and outcome bias; the path is to examine the design, not to root for the finding.

The review on heated tobacco is the clearest example of the problem. The review authors declare that they received nothing from manufacturers of tobacco products or e-cigarettes, but all 11 included trials were funded by tobacco companies (Tattan-Birch and colleagues, 2022). In some of them, the declaration said that all authors were employees of the company or worked for it under contract (Tattan-Birch and colleagues, 2022). The review concluded that research with independent funding on the efficacy and safety of these products is needed (Tattan-Birch and colleagues, 2022). An independent review of dependent studies inherits the dependence.

Conflict also appears in public, well-designed studies, and it should be read with the same standard. A large public biomarker analysis has a coauthor with frequent, unpaid contacts with an e-cigarette company, and a first author with fees from a manufacturer of cessation products (Goniewicz et al., 2018). This does not bring down the data, but it is information the reader has the right to weigh.

In the living Cochrane review on e-cigarettes for cessation, several authors took part in included studies and declare they did not decide on the inclusion, extraction or assessment of those studies; one author declares funding from a company that develops a cessation medication, and one author, travel expenses paid by a manufacturer of nicotine replacement products (Lindson et al., 2026). The review flags studies funded by the tobacco or e-cigarette industry and repeats the analyses without them (Lindson et al., 2026). This is the behavior to look for: declare, separate and test whether the result changes.

Funding also influences what the physician reads. An analysis of 421 publications on e-cigarettes in core clinical journals found that only about one in eight carried guidance for health professionals (Briganti et al., 2020). The same analysis showed that the themes changed over time, with fewer negative statements about toxic substances and more about gateway and appeal to young people (Briganti et al., 2020). What reaches the office is a slice, and knowing this already protects against the trap of reading only what confirms.

Dual use: when adding products does not reduce risk

Most promises assume a complete switch. In real life, many people use both: they keep smoking and add the alternative product. This pattern, called dual use, is the main trap in reading the promises, because the exposure reduction measured in a complete switch does not apply to those who keep smoking.

In a large population cohort, those who used both products smoked practically as much as those who only smoked and had the highest exposure to toxic substances of all groups (Goniewicz et al., 2018). Adding a product to the cigarette did not dilute exposure; it added to it.

The National Academies concluded there is no available evidence on whether prolonged e-cigarette use by those who keep smoking changes morbidity or mortality compared with those who only smoke (National Academies of Sciences, Engineering, and Medicine, 2018). They also considered insufficient the evidence that this use changes short-term adverse outcomes in several systems (National Academies of Sciences, Engineering, and Medicine, 2018). That is, for dual use, the promise of benefit has no basis.

In the cardiovascular cohort, the risk of those who used both products did not differ from the risk of those who only smoked, with a hazard ratio of 1.01 and a confidence interval of 0.81 to 1.26 (Berlowitz et al., 2022). The authors concluded that combining the cigarette with the e-cigarette does not reduce cardiovascular events and that stopping both products is necessary to reduce risk (Berlowitz et al., 2022). The reason is in the text about the curve that is not straight.

In the trials, the comparison of biomarkers between exclusive use and dual use was mixed and scarce, with no basis for promising benefit to those who keep smoking (Hartmann-Boyce et al., 2023).

What independent reviews show about cessation

The most relevant question for clinical practice is not whether the product is less toxic, but whether it helps people stop smoking. Here the two main categories have very different evidence.

For the electronic cigarette, the Cochrane living review included 80 randomized trials with 29861 participants; 12 were judged at low risk of bias and 41 at high risk (Lindson and colleagues, 2026). Compared with nicotine replacement therapy, the nicotine electronic cigarette increased abstinence after six months or more, with a relative risk of 1.61 and an interval of 1.23 to 2.12, in 11 studies and 4114 participants, high-certainty evidence (Lindson and colleagues, 2026). In absolute terms, this corresponds to about four more people not smoking for every 100 treated (Lindson and colleagues, 2026). When industry-funded studies were removed, the relative risk was 1.72, with an interval of 1.23 to 2.39 (Lindson and colleagues, 2026).

Compared with nicotine-free electronic cigarette, the relative risk was 1.34, with an interval of 1.05 to 1.69, in seven studies and 1918 participants, which represents about two more people not smoking for every 100 (Lindson and colleagues, 2026). Compared with behavioral support alone or no support, the relative risk was 1.75, with an interval of 1.39 to 2.20, in 11 studies and 7214 participants, but with low certainty due to risk of bias (Lindson and colleagues, 2026). The authors did not detect serious short-term harm, but they state that larger and longer trials are needed to assess safety (Lindson and colleagues, 2026).

Two details of the same review matter for reading it. The trials tested regulated nicotine products, and the authors warn that illicit products or products with other active substances may have different harm profiles (Lindson and colleagues, 2026). And, in the three trials that measured continued use after six months, the difference between electronic cigarette with and without nicotine was not clear, with a relative risk of 1.14 and an interval of 0.77 to 1.69, in 874 participants (Lindson and colleagues, 2026). Stopping smoking is not the same as stopping nicotine use, and trial follow-up still does not reach disease.

The independent umbrella review was more cautious when considering the whole body of evidence: it classified as limited the evidence that the nicotine electronic cigarette, used with clinical support, helps people stop (Banks and colleagues, 2023). The difference between the two reviews comes partly from the period covered and the type of study included, and reading the two side by side is a good exercise.

For heated tobacco, the situation is different. The Cochrane review found 13 studies, and none measured cessation (Tattan-Birch and colleagues, 2022). The authors' conclusion was that the product's effectiveness for stopping smoking remains uncertain (Tattan-Birch and colleagues, 2022). Two time-series studies showed a faster decline in cigarette sales after the product entered a market, but with very low-certainty evidence, because sales are an indirect measure of prevalence and other factors may explain the decline (Tattan-Birch and colleagues, 2022).

How this evidence enters each person's treatment choice is a matter of management, discussed in the text on how to choose among treatment options. Here, the point is about reading: a cessation promise only counts with confirmed abstinence after six months or more, in a trial with a comparator.

How to answer the patient who asks "is this less bad?"

The patient's question deserves a direct and honest answer, without a lecture and without advertising. One path is to separate three sentences. The first: completely switching from cigarettes to a combustion-free product reduces exposure to many toxic substances. The second: we still do not know the effect of this on disease over decades. The third: using both at the same time does not reduce heart risk. The three sentences are true at the same time.

The perception of harm that the patient brings influences what they will do. In a study of 2180 young adults who used some nicotine or tobacco product, about seven in ten did not see the e-cigarette as less harmful than the cigarette (Nagawa and colleagues, 2026). Those who did not see less harm were more likely to be using no product at all at the next assessment, with a relative risk ratio of 1.60, but also more likely to move to using only the cigarette, with a ratio of 3.81, always compared with exclusive e-cigarette use (Nagawa and colleagues, 2026). Raising alarm without explaining can push some people back to the more harmful product.

Perceptions also go wrong in unexpected directions. In an experiment with 897 adults who ranked 18 tobacco and nicotine products from most to least harmful, perceptions did not match the scientific literature for combusted products, smokeless tobacco and non-combusted products (DeAtley and colleagues, 2025). Some groups assigned high harm to nicotine replacement therapy itself, which is treatment (DeAtley and colleagues, 2025). Asking what the person thinks before explaining avoids answering a doubt they do not have.

The conversation works best when it starts from the person's goal. If they want to stop smoking, the path is evidence-based treatment, and listening for change talk helps find the next step. If they do not want to stop now, discussing intermediate goals honestly is part of deciding risk and prognosis with the person, without pretending that a partial reduction equals stopping. Tone matters as much as content, as the text on changing language in practice shows.

The same middle-ground reasoning appears in other harm reduction services, whose impact the clinician also needs to know how to read, as discussed in what changes for the clinician in supervised consumption rooms. In every case, the question is the same: reduction of what, for whom and with what evidence.

Frequently asked questions

Does fewer toxic substances mean a safe product?

No. It means less exposure to some substances, compared with smoking. Less exposure and demonstrated safety are different claims, as the text on surrogate outcomes discusses.

Does using an e-cigarette and a cigarette at the same time reduce risk?

There is no basis to say it does. In the cardiovascular cohort, the risk for those who used both did not differ from that of those who only smoked (Berlowitz and colleagues, 2022). Among dual users, exposure to toxic substances was the highest of all groups (Goniewicz and colleagues, 2018).

Does a heated tobacco product help people stop smoking?

It is not known. The Cochrane review found no study that measured cessation, and all included trials were funded by tobacco companies (Tattan-Birch and colleagues, 2022). Effectiveness for stopping remains uncertain.

How can I tell whether a study was funded by the tobacco industry?

Read the funding and conflicts of interest sections, check the authors' affiliations and the trial registry sponsor. Well-conducted reviews flag these studies and repeat the analyses without them, as the Cochrane review on e-cigarettes does (Lindson and colleagues, 2026).

Are e-cigarettes included in cessation reviews?

Yes. The Cochrane living review found high-certainty evidence that nicotine e-cigarettes increase abstinence after six months or more compared with nicotine replacement therapy (Lindson and colleagues, 2026). Choosing treatment for each person is discussed in the text on smoking cessation at every visit.

Does this text recommend any product?

No. It offers a script for reading promises and does not replace individual clinical assessment or guide treatment. No product or brand is recommended.

Final checklist

• Always ask what the comparator is: smoking, stopping or never using.
• Distinguish emission, exposure biomarker, harm biomarker and disease.
• Check the follow-up time and the number of events.
• Read the funding section and the conflicts of interest section.
• Check whether the review tested the result without the industry studies.
• Ask the patient whether use is exclusive or dual and how many cigarettes they smoke today.
• Require confirmed abstinence after six months for any cessation promise.
• Answer with three sentences: less exposure when switching completely, disease still unknown, dual use without benefit.

References

1. Banks E, Yazidjoglou A, Brown S, et al. Electronic cigarettes and health outcomes: umbrella and systematic review of the global evidence. Med J Aust. 2023. PMID 36939271. DOI 10.5694/mja2.51890.
2. Berlowitz JB, Xie W, Harlow AF, et al. E-cigarette use and risk of cardiovascular disease: a longitudinal analysis of the PATH Study (2013-2019). Circulation. 2022. PMID 35514292. DOI 10.1161/CIRCULATIONAHA.121.057369.
3. Briganti M, Wackowski OA, Delnevo CD, et al. Content analysis of electronic nicotine delivery system publications in core clinical journals from 2012 to 2018. Int J Environ Res Public Health. 2020. PMID 32218306. DOI 10.3390/ijerph17072201.
4. DeAtley T, Stone MD, Johnson AC, et al. Racial and ethnic variation in perceived relative harm of tobacco and nicotine products: an experimental study. BMJ Public Health. 2025. PMID 41262779. DOI 10.1136/bmjph-2025-002723.
5. Goniewicz ML, Smith DM, Edwards KC, et al. Comparison of nicotine and toxicant exposure in users of electronic cigarettes and combustible cigarettes. JAMA Netw Open. 2018. PMID 30646298. DOI 10.1001/jamanetworkopen.2018.5937.
6. Hartmann-Boyce J, Butler AR, Theodoulou A, et al. Biomarkers of potential harm in people switching from smoking tobacco to exclusive e-cigarette use, dual use or abstinence: secondary analysis of Cochrane systematic review of trials of e-cigarettes for smoking cessation. Addiction. 2023. PMID 36208090. DOI 10.1111/add.16063.
7. Htay ZW, Bhandari AKC, Parvin R, Abe SK. Effects of smokeless tobacco on cancer incidence and mortality: a global systematic review and meta-analysis. Cancer Causes Control. 2025. PMID 39718727. DOI 10.1007/s10552-024-01933-w.
8. Lindson N, Livingstone-Banks J, Butler AR, et al. Electronic cigarettes for smoking cessation. Cochrane Database Syst Rev. 2026. PMID 42642048. DOI 10.1002/14651858.CD010216.pub11.
9. Nagawa CS, Vogel EA, Richards VL, Cohn AM. Association between perceived relative harm of electronic cigarettes versus cigarettes on nicotine or tobacco use patterns in young adults: findings from the PATH study. Nicotine Tob Res. 2026. PMID 41934239. DOI 10.1093/ntr/ntag076.
10. National Academies of Sciences, Engineering, and Medicine. Public Health Consequences of E-Cigarettes. National Academies Press. 2018. PMID 29894118. DOI 10.17226/24952.
11. Tattan-Birch H, Hartmann-Boyce J, Kock L, et al. Heated tobacco products for smoking cessation and reducing smoking prevalence. Cochrane Database Syst Rev. 2022. PMID 34988969. DOI 10.1002/14651858.CD013790.pub2.