The safety and long-term health effects of using e-cigarettes or
other vaping products still aren’t well known. In September 2019,
federal and state health authorities began investigating an outbreak of a severe lung disease associated with e-cigarettes and other vaping products. We’re closely monitoring the situation and will update our content as soon as more information is available.
When people use tobacco products, some of the nicotine stays in their
system after they quit smoking. Medical tests can detect nicotine in
people’s urine, blood, saliva, hair, and nails.
When someone smokes a cigarette, their body absorbs up to 90 percent of
the nicotine. Traces of nicotine will linger long after individuals no
longer feel the effects.
How long does nicotine stay in the body?

This short half-life means that the immediate effects of nicotine go
away quickly, so people soon feel like they need another dose.
Doctors can use nicotine tests to measure levels of nicotine and its by-products in a person’s:
- urine
- blood
- saliva
- hair
- nails
Traces of nicotine may stay in the hair for longer, though people are
rarely asked to do a hair test unless they are taking part in research.
The exact length of time it takes for nicotine to clear differs between people:
- Nicotine may stay in the body for longer in adults aged over 65 years.
- Women tend to process nicotine more quickly than men, especially if they are taking birth control pills.
- The body will take longer to remove nicotine in people who have smoked more frequently and for longer.
How long does nicotine withdrawal last?
The severity and timescale of physical withdrawal symptoms will vary, depending on how much an individual smokes.A paper from 2010 suggests that people who smoke five or fewer cigarettes a day may not have intense physical symptoms because their bodies are less dependent on nicotine. However, they may still have emotional ties to smoking.
Symptoms of nicotine withdrawal are at their worst a few days to a
couple of weeks after smoking. The first week is usually the most
difficult, and symptoms gradually reduce over the following few weeks.
- anxiety or stress
- irritability
- trouble sleeping
- depression
- restlessness
- difficulty focusing
- increased appetite
The desire for nicotine may be worse in triggering situations. Examples of these may include times of stress or when having drinks with friends. Over time, these triggers become much less powerful.
Smoking vs. vaping

Vaping is a relatively recent invention, and so little research has
looked into its short- and long-term effects. Researchers do not yet
know whether the body processes nicotine differently from cigarettes or
vapes.
Also, it is difficult to tell how much nicotine people inhale from vaping. This is because vape solutions contain different quantities of nicotine. Furthermore, labeling has shown inaccuracy with a -89 to 28 percent variance between the label and the actual nicotine content.
Researchers are continuing to study the following factors that may determine how much nicotine people ingest when using a vape or e-cigarette:
- The amount of nicotine in the vaping solution.
- The efficiency with which vaping devices deliver nicotine.
- Differences in how people use vaping devices, including frequency and length of inhalation.
Testing methods for nicotine
Testing of people for nicotine is sometimes done for insurance or job-related reasons. Nicotine tests measure a person’s exposure to nicotine, and if they have been exposed, by how much. These tests look for traces of nicotine and other related substances, such as cotinine.
Cotinine is a more reliable measure of tobacco use because it stays in
the body for much longer. The half-life of nicotine is 2 hours, while
the half-life of cotinine is approximately 16 hours.
Testing can use the following different parts of the body for tissue samples:- urine
- saliva
- blood
- hair
- nails