What Ingredients Are in JUULpods and Other Vaping Products?

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January 2020 UPDATE: Recent illnesses have been associated with use of e-cigarettes (vaping). Since the specific causes of these lung injury cases are not yet known, the Centers for Disease Control and Prevention (CDC) recommends refraining from all vaping products.

While vaping has been touted by some to be a less harmful alternative to smoking, the vapor created by electronic cigarette devices is far from harmless. JUULpods (liquid cartridges used in JUUL devices) and other e-cigarette products contain ingredients that result in an aerosol that can contain potentially harmful substances like nicotine, metals, and toxins.

Here’s what is known about the different ingredients found vaping products like JUULpods and how they might impact your health. 


The bulk of vaping fluid is made up of solvents. These clear liquids serve as the base for the fluid and make vapor when they’re heated up—thus the name “vaping.”

The two most common solvents used in vaping products are propylene glycol and glycerin, with some products (like JUUL) containing a combination of the two. 

  • Propylene glycol: An odorless, tasteless fluid that absorbs water, this is used in cosmetics, food products, medicine, and other products to manage moisture.
  • Glycerin: Also known as vegetable glycerin or glycerol, glycerin is a fluid used in a range of industries. Like propylene glycol, glycerin is odorless with a syrupy consistency; however, it differs slightly in that it has a mild, sweet flavor to it. 

While the U.S. Food and Drug Administration (FDA) considers both of these solvents safe when ingested, what isn’t well known is how safe they are when heated up and inhaled.

Vaping devices like JUUL work by using hot coils to heat up liquids to create a vapor. But the temperature of the coils can cause the solvents to break down and form new chemicals.

For example, when propylene glycol is heated by the coils in an electronic cigarette, it can form acetol (hydroxyacetone) and 2-propen-1-ol (allyl alcohol); heated glycerin can form glycidol and acrolein. And both of the solvents can degrade and form formaldehyde, which can be toxic in high doses.

vaping sore throat
 Verywell / Luyi Wange


Traditionally, vaping manufacturers like JUUL have added flavors to their products to make them taste better to users. Flavorings are often used in food products to manufacture or enhance flavors, but the safety of these products can change when they’re inhaled as opposed to eaten or touched. 

Two examples of flavoring ingredients added to e-cigarettes are diacetyl and benzaldehyde. 


Diacetyl is a chemical sometimes added to vaping products to create rich flavors like butterscotch or caramel. Food manufacturers use this flavoring chemical in a wide range of capacities—perhaps most (in)famously in microwave popcorn; diacetyl smells and tastes like butter.

But while diacetyl is generally considered safe by the FDA when eaten, it can potentially wreak havoc in the lungs when it’s inhaled, leading to bronchiolitis obliterans, a condition more commonly known as “popcorn lung."


This is a flavoring that smells a little like almonds and is found in a broad range of products, including perfumes, medications, and e-cigarettes

Much of the research done on the safety of benzaldehyde has focused on ingestion, but there’s some evidence that breathing in large amounts of the chemical can irritate the respiratory tract and cause shortness of breath. 

The FDA now bans the manufacturing and sale of flavored vaping products (excluding menthol and tobacco). The new policy is effective as of Feb. 1, 2020. 

Risk of Flavorings for Young People

The tasty flavors often added to vaping products have been a big part of their appeal, especially for young people. Kid-friendly flavors like cotton candy or fruit punch have been particularly popular among teens, who cited flavorings as the most common ingredient in the vaping products they use.

Added flavors can also make e-fluids a poisoning risk for small children who mistake the fluid for candy or fruit juice. For small children, in particular, coming into contact with liquid nicotine—even through the skin—could lead to nausea, vomiting, and death. Poison control centers in the U.S. get thousands of calls every year related to e-cigarette device and liquid nicotine exposure, according to the National Poison Data System of the American Association of Poison Control Centers.

The FDA's enforcement policy to limit unauthorized flavors in electronic cigarettes came about because of these risks. However, some counterfeit or homemade products might continue to contain such ingredients. 


Vaping devices are also popular delivery mechanisms for mind-altering chemicals and additives, especially nicotine and THC. 


Many vaping products contain nicotine, the highly addictive substance found in traditional tobacco products. Nicotine affects the reward centers in the brain, making it hard to quit using nicotine once you start. The more you use nicotine, the more your brain starts to rely on it to get the same effect—and the harder it is to stop. 

But addiction isn’t the only risk associated with nicotine. It’s also been linked to a range of other health issues, including:

  • Cancer
  • Cardiovascular diseases and heart attacks.
  • Suppressed immune system
  • Premature labor, miscarriage, and other reproductive health issues 
  • Impaired cognitive functions like learning, concentration, or memory

Amount in E-Cigarettes

The amount of nicotine in e-cigarettes varies from one product to the next. For example, JUULpods have two different levels of nicotine: 40 milligrams (mg) labeled as 5% strength, and 23 mg labeled as 3% strength. A 5% strength pod has about the same amount of nicotine as a pack of cigarettes and roughly double that of many other e-cigarette brands.

The high levels of nicotine in JUUL products might come as a surprise to a lot of users. When surveyed, nearly two-thirds (63%) had no idea JUUL pods contained any nicotine at all. 

Not all vaping manufacturers report how much nicotine is in their products, but even when they do, analyses show what’s inside the vape juice doesn’t always match what is said on the packaging. One study, for example, detected measurable amounts of nicotine in some vaping products despite labels claiming the product to be nicotine-free.

Note: E-cigarettes have yet to be approved by the FDA as a form of nicotine replacement therapy or smoking cessation. 

Types of Nicotine in E-Cigarettes

And it’s not just the presence of nicotine that matters. The type of nicotine used in e-cigarette products can also affect how quickly the chemical is absorbed into the body, as well as how much a person is able to take in. 

JUUL, for example, uses a nicotine salt formulation—that is, nicotine extracted from natural tobacco leaves. It packs nearly the same punch of nicotine as smoking, but (when combined with benzoic acid, another ingredient in JUULpods) it goes down a lot smoother. That is, it doesn’t cause the same throat or chest irritation that happens with combustible cigarettes, allowing people to inhale more deeply or more frequently, potentially exposing them to even more nicotine. 

Most other vaping brands use a chemically altered form of nicotine known as freebase nicotine. Freebase nicotine is technically more potent than naturally-occurring tobacco nicotine salts, but tends not to bother the throat and chest. As a result, formulated nicotine salts used by manufacturers like JUUL are effectively stronger than the freebase type because they can use a higher concentration of nicotine without being harsh.

Nicotine in Young People

While traditional tobacco use among middle and high school students has remained pretty stagnant in recent years, e-cigarette use is climbing. The estimated number of high school students using e-cigarettes like JUUL jumped from 11.7% in 2017 to 27.5% in 2019.

Nicotine is particularly dangerous for teens and young adults because their brains aren't yet fully developed. As a result, developing an addiction to nicotine during adolescence could make them more likely to smoke or develop other substance use disorders (e.g., alcohol or cocaine) later in life.

As of December 20, 2019, 21 years old is the new legal age minimum for purchasing cigarettes, cigars, e-cigarettes, or any other tobacco products in the United States.


As marijuana use has become legalized and decriminalized in many parts of the U.S., e-cigarette products have started to include options to vape cannabis-derived substances like tetrahydrocannabinol (THC).

THC is a psychoactive chemical found in marijuana (specifically, the dried leaves and stems of the cannabis plant). It’s what makes people feel “high” when using marijuana and it can have some profound effects on the body.

Some health effects of THC include: 

  • Impaired body movement
  • Issues thinking or problem-solving
  • Loss of mental capacity, such as with memory or learning
  • Hallucinations or delusions (with high doses) 

In the summer of 2019, cases of serious lung issues tied to vaping began cropping up throughout the U.S. Many, though not all, of the people who got sick used vaping products that contained THC. As a result, the FDA and the CDC warned people not to use electronic cigarettes containing THC.

Vitamin E Acetate

Vitamin E acetate has been strongly linked to serious lung issues stemming from vaping. A 2020 study of 51 patients with vaping-associated lung injury found that vitamin E acetate was associated with their disease in 94% of cases.

Vitamin E acetate has been used as an additive in e-cigarettes, particularly those containing THC. It’s also a vitamin found in many foods as well as cosmetic skin products. It isn’t usually harmful when swallowed as a vitamin or applied topically, but when it’s inhaled, it can lead to abnormal lung functioning.

Because of the findings, according to the CDC, vitamin E acetate should not be added to any vaping products.


In some cases, ingredients in vaping devices weren’t put there on purpose. They’re a byproduct of the manufacturing process or debris from the devices themselves. Some of the contaminants found in e-cigarettes include ultrafine particulates and metals—both of which can be damaging to the lungs.

Ultrafine Particles 

Human lungs aren’t designed to handle foreign debris, which is part of why smoking is so harmful. When you inhale smoke from a cigarette, tiny pieces of burned, treated tobacco get into the delicate tissue of the lungs, sparking inflammation and opening the door for toxic chemicals to enter the bloodstream.

Vaping doesn’t burn tobacco leaves; it heats up fluids to create an aerosol. That vapor doesn’t contain a lot of the debris found in cigarettes, but it can still contain ultrafine particles that can irritate the sensitive tissue deep in the lungs. 


The tiny coils used to heat up liquids in vaping devices are often made of metal. Over time, tiny pieces of metal can make their way into the aerosol and, eventually, lung tissue.

Some of the metals found in e-cigarette vapor include:

  • Aluminum, a metal that, when inhaled, can damage the lungs and lead to asthma or pulmonary fibrosis
  • Chromium, a carcinogen linked to lung cancer when inhaled
  • Copper, which can irritate the lungs and cause coughing, pain, or runny nose
  • Iron, which can irritate the nose, throat, and lungs and lead to coughing, wheezing, or shortness of breath
  • Lead, a highly toxic metal that can damage the brain and kidneys—regardless of whether it’s inhaled or ingested
  • Manganese, which, when inhaled, can irritate the lungs and make it hard to breathe
  • Nickel, a carcinogen that can lead to lung cancer when inhaled, as well as chronic bronchitis, emphysema, and pulmonary fibrosis
  • Tin, which can lead to pneumoconiosis (a lung disease caused by mineral dusts) or inflammation in the lungs
  • Titanium, which can irritate the lungs and lead to shortness of breath and bronchitis

The types and concentrations of these metals vary widely from one product to the next; however, research shows that the amount of these metals in e-cigarette aerosol is often far above what is considered to be safe, especially when inhaled.  

One 2013 study found that the aerosol put out by e-cigarettes had just as much lead as some traditional cigarettes and even higher concentrations of other metals nickel and iron.

Secondhand Vaping

The harmful substances found in some e-cigarette aerosols might not just affect those who vape. Just like cigarettes could put others at risk of inhaling secondhand smoke, there is some evidence to suggest that secondhand vaping could increase the chances of a non-user being exposed to some ingredients found in e-cigarettes, particularly nicotine. 

A Word From Verywell 

Vaping products aren’t always clearly labeled, and some ingredients lists can be misleading or paint an incomplete picture—especially considering the chemical changes that can take place at different temperatures. Likewise, bootleg or home-brewed vaping products might contain other harmful substances not yet known.

It’s difficult to know what’s in any one product, and a lot more research is needed into how these ingredients might affect health long-term. That said, there’s enough evidence to show that the health risks of vaping could be substantial, especially for kids and young adults.

If you or someone you know is addicted to vaping, talk to your healthcare provider right away about how to quit.

24 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. Ellington S, Salvatore P, Ko J et al. Update: Product, Substance-Use, and Demographic Characteristics of Hospitalized Patients in a Nationwide Outbreak of E-cigarette, or Vaping, Product Use–Associated Lung Injury — United States, August 2019–January 2020. MMWR Morb Mortal Wkly Rep. 2020;69(2):44-49. doi:10.15585/mmwr.mm6902e2

  2. JUUL. JUULpod basics

  3. U.S. Food and Drug Administration. Code of federal regulations: 21CFR182.1320.

  4. U.S. Food & Drug Administration. Enforcement Priorities for Electronic Nicotine Delivery System (ENDS) and Other Deemed Products on the Market Without Premarket Authorization: Guidance for Industry.

  5. U.S. Food and Drug Administration. Code of federal regulations: 21CFR184.1278.

  6. New Jersey Department of Health and Senior Services. Hazardous substance fact sheet: benzaldehyde.

  7. National Institute on Drug Abuse. Teens and e-cigarettes.

  8. American Association of Poison Control Centers. E-Cigarettes and Liquid Nicotine.

  9. U.S. Food and Drug Administration. FDA finalizes enforcement policy on unauthorized flavored cartridge-based e-cigarettes that appeal to children, including fruit and mint.

  10. U.S. Department of Health and Human Services. The health consequences of smoking—50 years of progress: A report of the surgeon general.

  11. JUUL. How much nicotine is in a JUULpod?

  12. Truth initiative. How much nicotine is in JUUL?

  13. Truth Initiative. JUUL e-cigarettes gain popularity among youth, but awareness of nicotine presence remains low.

  14. Trehy M, Ye W, Hadwiger M et al. Analysis of Electronic Cigarette Cartridges, Refill Solutions, and Smoke for Nicotine and Nicotine Related Impurities. J Liq Chromatogr Relat Technol. 2011;34(14):1442-1458. doi:10.1080/10826076.2011.572213

  15. Cullen K, Gentzke A, Sawdey M et al. e-Cigarette Use Among Youth in the United States, 2019. JAMA. 2019;322(21):2095. doi:10.1001/jama.2019.18387

  16. U.S. Department of Health and Human Services. E-Cigarette Use Among Youth and Young Adults. A Report of the Surgeon General. Atlanta, GA: U.S. Department of Health and Human Services, Centers for Disease Control and Prevention, National Center for Chronic Disease Prevention and Health Promotion, Office on Smoking and Health, 2016.

  17. U.S. Food & Drug Administration. Selling Tobacco Products in Retail Stores.

  18. National Institute on Drug Abuse. What is marijuana?

  19. Centers for Disease Control and Prevention. Outbreak of lung injury associated with e-cigarette use, or vaping.

  20. Blount B, Karwowski M, Shields P et al. Vitamin E Acetate in Bronchoalveolar-Lavage Fluid Associated with EVALI. New England Journal of Medicine. 2020;382(8):697-705. doi:10.1056/nejmoa1916433

  21. Geiss O, Bianchi I, Barahona F, Barrero-moreno J. Characterisation of mainstream and passive vapours emitted by selected electronic cigarettes. Int J Hyg Environ Health. 2015;218(1):169-80. doi:10.1016/j.ijheh.2014.10.001

  22. Olmedo P, Goessler W, Tanda S, Grau-Perez M, Jarmul S, Aherrera A, et al. Metal concentrations in e-cigarette liquid and aerosol samples: The contribution of metallic coils. Envir Health Persp. 2018;126(2). doi:10.1289/EHP2175

  23. Williams M, Villarreal A, Bozhilov K, Lin S, Talbot P. Metal and Silicate Particles Including Nanoparticles Are Present in Electronic Cigarette Cartomizer Fluid and Aerosol. PLoS ONE. 2013;8(3):e57987. doi:10.1371/journal.pone.0057987 

  24. Czogala J, Goniewicz ML, Fidelus B, Zielinska-danch W, Travers MJ, Sobczak A. Secondhand exposure to vapors from electronic cigarettes. Nicotine Tob Res. 2014;16(6):655-62. doi:10.1093/ntr/ntt203

Additional Reading

By Robyn Correll, MPH
Robyn Correll, MPH holds a master of public health degree and has over a decade of experience working in the prevention of infectious diseases.