The ongoing debate over whether vaping is safer than smoking continues to attract attention from researchers, regulators, and public health officials. Across nicotine research, leading public health bodies now generally agree that vaping is substantially less harmful than smoking combustible cigarettes, though not without risks. England’s 2022 government-commissioned evidence update concluded that, based on current findings, the health risks from nicotine vaping are “substantially lower” than from smoking, while still acknowledging uncertainties surrounding long-term effects and youth usage.

The most recent Cochrane Review, a gold-standard source for scientific evidence, found strong evidence that nicotine e-cigarettes help more people quit smoking than traditional nicotine replacement therapies. For adults unable or unwilling to quit nicotine entirely, switching completely from cigarettes to regulated e-cigarettes reduces exposure to toxicants and improves quit rates compared with patches or gum alone.

However, the 2019–2020 outbreak of e-cigarette or vaping product use–associated lung injury, known as EVALI, highlighted the risks associated with unregulated or illicit products. Investigations by the U.S. Centers for Disease Control and Prevention (CDC) linked most EVALI cases to illegal THC cartridges adulterated with vitamin E acetate. Once this ingredient was removed from supply chains and enforcement increased, reported cases declined significantly. The episode reinforced the importance of sourcing only regulated and lab-tested vaping products.

When it comes to cannabis, the available evidence is more limited but follows a similar trend regarding combustion. The U.S. National Academies found substantial evidence that smoking cannabis is linked with chronic bronchitis symptoms and other respiratory issues. Many of these harms stem from smoke and its byproducts rather than cannabinoids themselves, suggesting that avoiding combustion likely reduces respiratory risk.

Small clinical studies comparing smoked versus vaporized cannabis have found that vaporization delivers comparable THC levels with markedly lower carbon monoxide exposure, indicating reduced intake of combustion-related toxins. Still, the evidence base remains relatively small, and researchers emphasize that device quality, temperature control, and product purity all play a critical role in determining safety outcomes.

Overall, the evidence points to vaping as a less harmful alternative to smoking, provided consumers use legal, regulated products. For adult smokers who switch completely to vaping, data suggest substantially reduced exposure to harmful chemicals and greater success in quitting cigarettes. For cannabis consumers, vaporization likely lowers inhalation of toxic byproducts compared to smoking, but long-term data are limited. The key takeaway is that “safer” does not mean “safe.” Non-smokers, especially youth, should not begin vaping, and consumers should remain cautious about unregulated products.