• E-cigarettes have the potential to benefit adults who smoke and who are not pregnant if used as a complete substitute for regular cigarettes and other smoked tobacco products.
• E-cigarettes are not safe for youth, young adults, pregnant adults, as well as adults who do not currently use tobacco products.
• While e-cigarettes have the potential to benefit some people and harm others, scientists still have a lot to learn about whether e-cigarettes are effective in helping adults quit smoking.
• If you`ve never smoked or used other tobacco products or e-cigarettes, don`t start.
• Additional research can help understand long-term health effects.

• E-cigarettes come in many shapes and sizes. Most have a battery, a heating element, and a place to hold a liquid.
• E-cigarettes produce an aerosol by heating a liquid that usually contains nicotine-the addictive drug in regular cigarettes, cigars, and other tobacco products-flavorings, and other chemicals that help to make the aerosol. Users inhale this aerosol into their lungs. Bystanders can also breathe in this aerosol when the user exhales into the air.
• E-cigarettes are known by many different names. They are sometimes called [e-cigs," [e-hookahs," [mods," [vape pens," [vapes," [tank systems," and [electronic nicotine delivery systems (ENDS)."
• Some e-cigarettes are made to look like regular cigarettes, cigars, or pipes. Some resemble pens, USB sticks, and other everyday items. Larger devices such as tank systems, or [mods," do not resemble other tobacco products.
• Using an e-cigarette is sometimes called [vaping."
• E-cigarettes can be used to deliver marijuana and other drugs.

The e-cigarette aerosol that users breathe from the device and exhale can contain harmful and potentially harmful substances, including:

• Nicotine
• Ultrafine particles that can be inhaled deep into the lungs
• Flavoring such as diacetyl, a chemical linked to a serious lung disease
• Volatile organic compounds
• Cancer-causing chemicals
• Heavy metals such as nickel, tin, and lead1

It is difficult for consumers to know what e-cigarette products contain. For example, some e-cigarettes marketed as containing zero percent nicotine have been found to contain nicotine.2

What is in e-cigarette aerosol?

Most e-cigarettes contain nicotine, which is addictive and toxic to developing fetuses. Nicotine exposure can also harm adolescent and young adult brain development, which continues into the early to mid-20s.1 E-cigarette aerosol can contain chemicals that are harmful to the lungs. And youth e-cigarette use is associated with the use of other tobacco products, including cigarettes.

For more information about the risks of e-cigarettes for young people, visit Quick Facts on the Risks of E-cigarettes for Kids, Teens, and Young Adults.

Yes-but that doesn`t mean e-cigarettes are safe. E-cigarette aerosol generally contains fewer toxic chemicals than the deadly mix of 7,000 chemicals in smoke from regular cigarettes.3 However, e-cigarette aerosol is not harmless. It can contain harmful and potentially harmful substances, including nicotine, heavy metals like lead, volatile organic compounds, and cancer-causing agents.1

E-cigarettes are not currently approved by the FDA as a quit smoking aid. The U.S. Preventive Services Task Force, a group of health experts that makes recommendations about preventive health care, has concluded that evidence is insufficient to recommend e-cigarettes for smoking cessation in adults, including pregnant adults.3

However, e-cigarettes may help non-pregnant adults who smoke if used as a complete substitute for all cigarettes and other smoked tobacco products.

• To date, the few studies on the issue are mixed. A Cochrane Review found evidence from two randomized controlled trials that e-cigarettes with nicotine can help adults who smoke stop smoking in the long term compared with placebo (non-nicotine) e-cigarettes.4 However, there are some limitations to the existing research, including the small number of trials, small sample sizes, and wide margins of error around the estimates.
• A recent CDC study [PDF – 197 KB] found that many adults are using e-cigarettes in an attempt to quit smoking.5 However, most adult e-cigarette users do not stop smoking cigarettes and are instead continuing to use both products (known as [dual use").7 Dual use is not an effective way to safeguard your health, whether you`re using e-cigarettes, smokeless tobacco, or other tobacco products in addition to regular cigarettes. Because smoking even a few cigarettes a day can be dangerous,6 quitting smoking completely is very important to protect your health.

E-cigarettes are the most commonly used tobacco product among youth.

• In 2022, 2.55 million U.S. middle and high school students used e-cigarettes in the past 30 days, including 3.3% (380,000) of middle school students and 14.1% (2.14 million) of high school students.9
• In 2020, 3.7% of U.S. adults currently used e-cigarettes.10
• In 2019, among current adult e-cigarette users overall, 36.9% also currently smoked cigarettes, 39.5% formerly smoked cigarettes, and 23.6% had never smoked cigarettes.11
• Among current adult e-cigarette users, the percentage who have never smoked cigarettes is highest among those aged 18–24 years (56.0%), and is lower in older age groups.11