Health Topic

E-Cigarettes

Smoking e-cigarettes, or vaping, may not be as safe as you might think. An e-cigarette contains nicotine which is harmful to your health. Learn more.

Reviewed Reviewed by a registered pharmacistGeneral information

Also called: E-Cigs · Electronic Cigarettes · Personal Vaporizer

Important: This page is general information, not medical advice. It does not recommend or prescribe any treatment. Always consult your doctor or pharmacist before starting, stopping or changing any medicine.

About E-Cigarettes

E-cigarettes, or electronic cigarettes, are battery-operated smoking devices. They often look like cigarettes, but work differently. Using an e-cigarette is called vaping. The user puffs on the mouthpiece of a cartridge. This causes a vaporizer to heat the liquid inside the cartridge. The liquid contains nicotine, flavorings, and other chemicals. The heated liquid turns into the vapor that is inhaled.

Some people think that e-cigarettes are safer than cigarettes, and that they can be used to help people quit smoking. But not much is known about the health risks of using them, or whether they do help people quit smoking. However we do know about some dangers of e-cigarettes:

  • They contain nicotine, which is addictive
  • They contain other potentially harmful chemicals
  • There is a link between e-cigarette use and tobacco cigarette use in teens
  • The liquid in e-cigarettes can cause nicotine poisoning if someone drinks, sniffs, or touches it

It sits within Substance Use and Disorders and Lungs and Breathing.

The lead U.S. institute for this subject is the National Institute on Drug Abuse.

When to speak to someone. Reading about a topic cannot tell you whether it applies to you. Speak to a doctor or pharmacist if symptoms are severe, sudden, getting worse, or simply not going away — and seek emergency care immediately for chest pain, breathing difficulty, sudden weakness or confusion, or a serious allergic reaction.

Research on E-Cigarettes

482 studies areregistered for this condition on ClinicalTrials.gov, the U.S. National Library of Medicine's public registry. A selection is below — the links go straight to the registry entry, not to a summary of ours.

What a registered study does and does not mean. Registration means a study exists and has been declared publicly. It says nothing about whether the treatment being tested works, is safe, or is available to you. Many studies find no benefit — that is what research is for. Never seek out an experimental treatment on the strength of a registry entry alone.

Research currently under way

Research already completed

Study data from ClinicalTrials.gov, a service of the U.S. National Library of Medicine. Retrieved 2026-07-30. Registry entries are supplied by study sponsors and investigators; ClinicalTrials.gov does not verify their scientific validity. PocketsInfo is not affiliated with, and not endorsed by, the NLM or the NIH.

Where to read more

Rather than paraphrase, we point you to the primary sources. Every link below is to a government health agency, a national institute or a recognised medical body — grouped by what you are trying to find out.

Learn More

Clinical Trials

Medical subject headings

Clinicians and researchers index this subject under Electronic Nicotine Delivery Systems. These are the terms to use when searching medical literature.

This page is built from the MedlinePlus health topic record for E-Cigarettes, a service of the U.S. National Library of Medicine (NLM), National Institutes of Health. Information is from MedlinePlus.gov. PocketsInfo is not affiliated with, and is not endorsed by, the NLM or the NIH. Retrieved 30 July 2026.