Short answer: neither is “healthy”, and nobody can yet say for certain which is less harmful over a lifetime. Both expose users to fewer of the measured toxicants in cigarette smoke. IQOS heats real tobacco, and in the few direct comparisons it leaves more tobacco-related toxicants than a nicotine vape. But there are no long-term health studies for either, and much of the heated tobacco research is paid for by the company that makes it. The lowest-risk choice is not to use either. This page sets out what the evidence does and doesn’t show, with sources.

What each product is

Vape (e-cigarette) IQOS (heated tobacco)
What’s heated A liquid: propylene glycol, glycerine, nicotine and flavourings A stick of processed tobacco leaf (HEETS, or TEREA for IQOS ILUMA)
Tobacco leaf No Yes
How A battery-powered coil turns the liquid into an aerosol The tobacco is heated without being set alight. Older IQOS uses a blade (Philip Morris gives a maximum of 350 °C); ILUMA heats a metal strip inside the TEREA stick by induction
Nicotine Yes, strength varies by product Yes, from the tobacco
Long-term health data None yet; most evidence covers about a year or less None yet; most trials last a few months or less

A burning cigarette reaches several hundred degrees hotter than either. Most of the harm from smoking comes from burning tobacco, which is why both products are pitched as alternatives. Not burning reduces some toxicants. It doesn’t remove all of them, and it doesn’t make either product safe.

What’s in the aerosol

IQOS vs cigarettes. Philip Morris’s own testing reports large reductions in the chemicals it measured. An independent reanalysis of that data by researchers at UCSF (St Helen et al., Tobacco Control, 2018) agreed that all 58 listed chemicals were lower in IQOS than in a reference cigarette. But it also found 56 other substances that weren’t on the list and were higher in IQOS: 22 by more than double, 7 by more than ten times. What those mean for health isn’t known. A 2017 Swiss study (Auer et al., JAMA Internal Medicine) found the same classes of harmful chemicals in IQOS emissions as in cigarette smoke, in different amounts.

IQOS vs a vape. Direct comparisons are few. One study measured carbonyls (a family of irritant and cancer-linked chemicals) from a cigarette, IQOS and an e-cigarette (Farsalinos et al., Addiction, 2018). IQOS was 85–95% lower than the cigarette for formaldehyde, acetaldehyde and acrolein, but still higher than the e-cigarette.

Charring. An independent test of the older blade IQOS (Davis et al., Tobacco Control, 2019) found signs of the tobacco charring and the filter’s plastic film melting, more so when the device wasn’t cleaned. That test was on HEETS and the blade device, not on ILUMA and TEREA.

A systematic review of 31 studies (Simonavicius et al., Tobacco Control, 2019) concluded heated tobacco gives off fewer toxicants than cigarettes. Independent and industry results were broadly similar, but 20 of the 31 studies had tobacco industry links.

What ends up in the body

Lower emissions only matter if users actually take in less. Studies measure this with biomarkers in blood or urine.

  • Vaping: long-term vape-only users in a UK study had about 97% less of a tobacco-specific carcinogen marker (NNAL) than smokers (Shahab et al., Annals of Internal Medicine, 2017). It was a snapshot of a self-selected group, not a trial.
  • Heated tobacco: the Cochrane review (Tattan-Birch et al., 2022) found moderate-certainty evidence that people who switch have lower toxicant exposure than smokers, but higher than people who use neither. Every trial it included was funded by the tobacco industry.
  • Harm markers, not just exposure: a 2025 review of 143 markers of potential harm (inflammation, heart and lung function and so on) found mixed results for heated tobacco, with “no clear indication of harm or benefit, even compared with cigarettes” (Braznell et al., Tobacco Control, 2025). Most of the 40 studies were industry-linked and short.
  • Side by side: an international study comparing users in Japan (heated tobacco) and Canada (vapes) found higher nicotine, NNK and acrolein exposure in the heated tobacco users (ITC Project, 2018–19 data). Because the two groups were in different countries, the comparison isn’t clean.

What health authorities say

  • US FDA: in 2020 it let IQOS be marketed with a reduced exposure claim: it heats rather than burns tobacco, and switching completely reduces exposure to harmful chemicals. It did not allow a claim that IQOS reduces the risk of disease. The order was renewed in April 2026. The FDA’s line: there is no safe tobacco product (FDA).
  • UK (Office for Health Improvement and Disparities, 2022): in the short and medium term, vaping poses a small fraction of the risks of smoking, but it is not risk-free, particularly for people who have never smoked (GOV.UK). Public Health England said in 2018 it was not clear heated tobacco offered any advantage over vaping.
  • WHO: heated tobacco products are tobacco products, and lower exposure “does not render them harmless, nor does it translate to reduced risk” (WHO, 2020). It also says e-cigarettes haven’t been shown to help people quit at population level.
  • US National Academies (2018): conclusive evidence that switching completely from cigarettes to e-cigarettes reduces exposure to many toxicants and carcinogens; substantial evidence that young people who vape are more likely to try smoking (NASEM).
  • Australia: the NHMRC says e-cigarettes can be harmful and all users are exposed to harm (NHMRC). An ANU review commissioned by the Department of Health (Banks et al., Medical Journal of Australia, 2023) found conclusive evidence that vaping can cause poisoning, burns and injuries from faulty devices, and acute lung injury, and too little evidence yet on heart disease and cancer. The Department of Health says there is no evidence heated tobacco is safe or less harmful than other tobacco products.

Quitting: does either help?

For vapes, the Cochrane living review of e-cigarettes for quitting smoking, updated most recently in 2025, has found that more people stop smoking with nicotine e-cigarettes than with nicotine patches or gum (Lindson et al., Cochrane). For heated tobacco there is no such evidence: the 2022 Cochrane review found no studies that measured quitting. Philip Morris itself says IQOS is not a cessation aid. In Australia, free support is available from Quitline on 13 7848.

Risks both share

  • Nicotine addiction. Both deliver nicotine, which is addictive and raises heart rate and blood pressure.
  • Dual use. Most of the benefit in the studies above comes from switching completely. Using either alongside cigarettes keeps exposure high.
  • Unknown long-term effects. Vapes have been common for about 15 years and ILUMA for a few. Diseases like cancer and COPD take decades to show.
  • Not for non-smokers. For someone who doesn’t smoke, either one adds risk; there is nothing to reduce.

EVALI, the lung injury outbreak in the US in 2019–20, was strongly linked by the CDC to vitamin E acetate in illicit THC vapes, not to nicotine vapes (CDC).

So which is “healthier”?

On what’s been measured so far, a nicotine vape exposes users to fewer tobacco-derived toxicants than IQOS, because it contains no tobacco leaf. IQOS, in turn, exposes users to fewer of the measured toxicants than cigarettes. That is a ranking of exposure, not proof of lower disease risk, and neither product has been shown to be safe. If you don’t smoke, don’t start either. If you smoke, quitting nicotine completely does the most good, and your GP, pharmacist or Quitline can help.

Questions

Is IQOS better than vaping?

Not on current evidence. In the few direct comparisons, IQOS emissions and users’ exposure to some toxicants were higher than for nicotine vapes, since IQOS heats real tobacco. Neither has long-term health data.

Is IQOS less harmful than cigarettes?

It exposes users to lower levels of many measured toxicants, and the US FDA allows a reduced-exposure claim. It has not been shown to reduce the risk of disease, and the FDA did not allow that claim.

Does IQOS have tar?

“Tar” is the residue of burning, and IQOS doesn’t burn tobacco in the same way. But its aerosol still contains particles and many of the same chemical classes found in cigarette smoke, so “no tar” doesn’t mean no harmful residue.

Is IQOS smoke or vapour?

Philip Morris calls it an aerosol. Some independent researchers argue it meets scientific definitions of smoke because it contains the same kinds of combustion-related chemicals, at lower levels.

Is heated tobacco safer than vaping for your lungs?

There is no evidence that it is. Both deliver an aerosol into the lungs; IQOS adds tobacco-derived compounds. Long-term lung outcomes haven’t been studied for either.

Does vaping or IQOS help you quit smoking?

Cochrane reviews find nicotine vapes help more people quit than nicotine patches or gum. There’s no comparable evidence for heated tobacco. Talk to a GP or pharmacist, or call Quitline on 13 7848.