Nicotine-free vapes are not risk-free. While they eliminate nicotine addiction, a systematic review published in the Journal of Clinical Medicine found that nicotine-free e-cigarettes produce measurable acute cardiovascular effects, including endothelial dysfunction, oxidative stress, and increased arterial stiffness.
This article examines the evidence from peer-reviewed research and explains the documented risks and benefits of zero-nicotine vaping — so you can have a complete, factual answer to the question "Are nicotine-free vapes safe?"
What is a Nicotine-Free Vape?
Nicotine-free vape juice (also called zero-nicotine e-liquid) is a liquid used in vapes that contains no nicotine. These products come in various flavors and are designed to mimic the sensory experience of vaping without the addictive component. The main ingredients typically include:
Propylene Glycol (PG) — A clear, odorless compound that creates a smooth, consistent vapor and carries flavor. PG is also responsible for the familiar "throat hit" associated with traditional smoking.
Vegetable Glycerin (VG) — A thicker, sweeter liquid derived from plant oils such as soy, palm, or coconut. It creates dense clouds of vapor and gives vape juice a slight sweetness.
Flavorings — Food-grade flavorings bring variety to nicotine-free vape juices. A critical distinction: FDA GRAS (Generally Recognized as Safe) certification covers eating these substances, not inhaling them. The safety profile for inhalation is different and less understood.
Optional Additives — Some products include water or minor flavor enhancers to adjust consistency or improve the experience.
The Mislabeling Problem
There is a significant concern about products sold as nicotine-free. An investigation by The Examination in September 2025 found that products advertised as nicotine-free contained undisclosed 6-methyl nicotine, a synthetic nicotine analog that preclinical studies suggest may be more potent than regular nicotine and similarly addictive. Some products also contain nicotinamide (a vitamin B3 derivative) marketed as an alternative nicotine analog, though its safety profile for inhalation remains unknown.
Laboratory testing found that concentrations of these analogs in e-liquids often diverged significantly from what was listed on product labels. When buying nicotine-free e-liquid, look for a Certificate of Analysis (COA) from a third-party lab.
Are Nicotine-Free Vapes Safer Than Smoking Cigarettes?
Yes — nicotine-free vapes are considerably safer than combusted tobacco cigarettes. Cigarettes produce thousands of chemicals, roughly 70 of which are known carcinogens, through the process of combustion. Nicotine-free vapes don't involve combustion, so they produce no tar, no carbon monoxide, and none of the combustion-specific carcinogens that drive lung cancer, COPD, and cardiovascular disease from smoking.
However, "safer than cigarettes" is not the same as "safe." The December 2025 systematic review explicitly concluded that nicotine-free products should not be regarded as risk-free. If you already smoke, switching to a nicotine-free vape is a meaningful harm-reduction step. If you don't currently smoke, no major health authority — including the CDC, American Heart Association, or UK NHS — recommends starting any form of vaping.
Benefits of Vaping Without Nicotine
Compared to vaping with nicotine, zero-nicotine vape juice offers several distinct advantages:
No chemical addiction risk — without nicotine, there is no chemical dependency, no withdrawal symptoms, and no compulsion to increase use.
No nicotine-specific cardiovascular stimulation — nicotine causes vasoconstriction and raises heart rate and blood pressure. Nicotine-free juice doesn't cause these nicotine-specific effects (though the aerosol itself can still affect blood vessels — see the risks section below).
Cleaner flavor — nicotine adds a bitter, harsh throat note that masks flavor nuance. Zero-nicotine juice delivers a smoother, more pronounced taste profile.
Lower accidental-ingestion toxicity — nicotine is acutely toxic to children and pets. Zero-nicotine juice poses no nicotine-poisoning risk.
Behavioral ritual without chemical dependency — useful for ex-smokers who want to preserve the hand-to-mouth habit while moving past nicotine.
Flavor-driven vaping — for people who enjoy vaping as a hobby, zero-nicotine juice removes the only pharmacologically active ingredient.
None of these benefits eliminate the underlying aerosol risks. The benefits are real, but they apply relative to nicotine vapes and cigarettes — not relative to not vaping at all.
Side Effects of Nicotine-Free Vape Juice
Vaping without nicotine can lead to several side effects:
Throat and Mouth Irritation — Heating and inhaling vapor can cause a tingling sensation or "throat hit." Research has shown that even a single puff from a nicotine-free device can cause measurable propylene glycol and glycerol irritation. Those sensitive to PG may experience persistent discomfort.
Dry Mouth — PG and VG are humectants that absorb moisture, potentially leading to dryness in the mouth or throat. Staying hydrated before and after vaping can help alleviate this sensation.
Increased Coughing — Beginners may experience coughing as their airways adjust to inhaling vapor, particularly if the vapor is dense or the inhalation technique is unfamiliar.
Mild Dizziness or Nausea — Though rare, some users experience slight dizziness or nausea, particularly after deep inhales or concentrated flavors.
Behavioral/Process Addiction — Even without nicotine, the hand-to-mouth habit and ritual of vaping can create psychological dependency. The sensory experience alone can reinforce habitual behavior that becomes difficult to break.
Health Risks of Vaping Without Nicotine
Nicotine-free vapes carry documented risks, especially with repeated, long-term use.
Cardiovascular Effects
The December 2025 systematic review in the Journal of Clinical Medicine analyzed nine studies on nicotine-free e-cigarettes and found that human trials consistently demonstrated acute vascular impairments — including endothelial dysfunction, oxidative stress, increased arterial stiffness, and transient blood pressure elevations.
A separate NIH-funded MRI study published in Radiology examined 31 healthy adults in their 20s and 30s who had never smoked or vaped. After just 16 puffs from a nicotine-free e-cigarette, MRI imaging of the femoral artery showed reduced blood flow compared to baseline — demonstrating measurable vascular changes within 60 minutes of a single exposure. This suggests the aerosol itself, not the nicotine, triggers the vascular response.
Exposure to Harmful Substances
When heated, PG and VG undergo thermal degradation, generating carbonyl compounds such as formaldehyde, acetaldehyde, and acrolein — the same class of chemicals found in cigarette smoke. Research published in Toxicology Letters (2025) confirmed that these thermal degradation byproducts contribute significantly to oxidative stress, airway inflammation, and increased cancer risk. Higher-power devices with sub-ohm capabilities generate higher concentrations of these byproducts.
Popcorn Lung Risk (Diacetyl)
Popcorn lung (bronchiolitis obliterans) is a severe, irreversible lung condition linked to inhaling diacetyl — a flavoring chemical first associated with respiratory disease in microwave popcorn factory workers, where workers exposed to high concentrations developed permanent scarring of the small airways.
Some vape juices have contained diacetyl. A Harvard T.H. Chan School of Public Health study tested 51 flavored e-cigarettes and found diacetyl in 39 of them — approximately 75%.
Potential for Inflammation
Research has demonstrated that exposure to flavored e-liquids without nicotine triggers inflammatory responses in lung cells. Flavoring chemicals like cinnamaldehyde and vanillin have been shown to impair mitochondrial function and induce cytotoxicity in vascular endothelial cells.
Allergic Reactions
A small portion of vapers are allergic to ingredients like propylene glycol, flavorings, or additives, experiencing itchy throat, sneezing, watery eyes, or rarely — more severe reactions.
Exposure to Heavy Metals
Research has shown that vape devices can release metals like aluminum, lead, nickel, and chromium from heating elements. These metals may enter the vapor and expose users to potential health risks regardless of nicotine content. Device quality and coil condition directly affect metal exposure levels.
Ingredients to Avoid in Nicotine-Free Vapes
Specific flavoring agents, sweeteners, and contaminants can increase health risks. Consider avoiding:
Diacetyl — linked to popcorn lung (bronchiolitis obliterans).
Acetoin and Acetylpropionyl — flavor compounds linked to respiratory risks.
Artificial Sweeteners — can produce undesirable chemical byproducts when heated.
Nicotine-Free Vapes vs. Nicotine Vapes vs. Cigarettes
Who Should Avoid Nicotine-Free Vapes?
The following groups should avoid vaping of any kind:
People with Respiratory Issues — If you have asthma, chronic bronchitis, or other lung conditions, vaping may worsen symptoms.
Pregnant Women — Vaping during pregnancy can expose the developing baby to harmful byproducts. Animal studies have demonstrated transplacental transfer of glycerol, aluminum, chromium, and nickel from e-cigarette exposure, suggesting potential risks to fetal development.
People with Ingredient Sensitivity — If you're allergic to propylene glycol, flavorings, or other standard components, avoid vaping to prevent discomfort or allergic reactions.
Minors and Adolescents — A Norwegian longitudinal study found that 66% of adolescent vapers used nicotine-free products. Adolescent lungs and brains are still developing, and inhaling vaporized chemicals can impact growth, cognitive function, and overall health. The CDC advises against any vape use by teens, with or without nicotine.
People with Cardiovascular Conditions — Given acute vascular effects including endothelial dysfunction and increased arterial stiffness, individuals with existing heart conditions should avoid nicotine-free vaping
Conclusion
Are nicotine-free vapes safe? The evidence is clear: they are not risk-free. While zero-nicotine vaping eliminates addiction potential and avoids nicotine-specific cardiovascular effects, research shows measurable acute harms including oxidative stress, endothelial dysfunction, arterial stiffness, and inflammation — even without nicotine.
Zero-nicotine vaping is safer than smoking cigarettes and safer than nicotine vapes. It is not safe. If you choose to vape, be mindful of the ingredients, watch for signs of discomfort, and choose brands that prioritize third-party testing and transparency. Stay informed and make the best decision for your health.