How long nicotine stays in your system and ways to clear it out more quickly

The exact length of time that cotinine is detectable in your blood may vary depending on your genetic makeup and the amount of nicotine that you were exposed to. Testing with blood may also be less sensitive than testing with urine. This could lead to false negatives or positives.

How Long Does Nicotine Stay in Your System?

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The time nicotine stays in your system depends on how long and how often you’re exposed to it. It also depends on whether you smoked it, chewed it, or inhaled it second-hand.

Whenever you smoke or chew tobacco or inhale secondhand smoke from a cigarette, nicotine is absorbed into your bloodstream.

From there, enzymes in your liver break most of the nicotine down into cotinine. The amount of cotinine will increase with the amount of nicotine you ingest. These substances are eventually eliminated through your kidneys as urine.

Cotinine, nicotine’s main breakdown product, may be used to determine if someone was exposed to nicotine.

According to a 2016 review of literature , cotinine has high sensitivity and a longer half-life compared to other breakdown products of nicotine. Testing for it can usually differentiate people who smoke cigarettes from people who may have had indirect exposure.

How long it stays in your system will depend on how you ingested the nicotine and how frequently it is ingested.

Keep reading to learn how long nicotine can be detected in your urine, blood, saliva, and hair.

Q:

If I smoke one cigarette, how much nicotine will I ingest?

A:

1 milligram (mg) of nicotine per cigarette

Answers represent the opinions of our medical experts. All content is strictly informational and should not be considered medical advice.

Cotinine has a half-life of about 16 hours , according to the Centers for Disease Control and Prevention (CDC). However, it may be as long as 40 hours , according to a 2016 research review. A half-life refers to the number of hours before half of the cotinine will have left your system.

However, tests for this metabolite can detect cotinine even after it has reached this point.

Concentrations of cotinine in urine are about 4 to 6 times higher than in blood plasma or saliva.

A 2019 study used cotinine urine tests on people preparing for bariatric surgery to determine adherence to pre-surgery instructions. According to the study’s authors, the cotinine urine test provided high sensitivity and specificity for smoking in at least the previous 72 hours.

Another study from 2020 found that cotinine may still be detectable in urine for at least 8 weeks .

However, the way each person’s body metabolizes nicotine to create cotinine is different. Genetic differences can also affect the amount of time cotinine is detectable in your body.

According to research summarized by the CDC , non-Hispanic Black Americans may metabolize cotinine more slowly than non-Hispanic white Americans.

A positive urine test can depend on when you provide a urine sample relative to the last time you ingested nicotine. If you’re a current smoker, the test show urine cotinine levels of 1,000 to 8,000 ng/mL.

People who smoke but go 2 weeks without nicotine exposure before testing may show urine cotinine levels of less than 50 ng/mL.

Each lab may have different reference ranges for positivity, so it’s important to discuss the results with a doctor or technician.

People with heavy exposure to secondhand smoke may test at levels between 1 and 10 ng/mL .

Nicotine can be measured in your blood and saliva, but because cotinine has a longer half-life, testing for cotinine is typically preferred. According to 2016 research , the half-life of cotinine is the same whether tested for in your blood plasma, urine, or saliva.

However, all of these molecules have different cut-off points for detection. Some sources estimate that it may be detectable at least 3 days after exposure.

A 2012 review that looked at methods for assessing environmental exposure to cigarette smoke found that blood cotinine levels may reach their half-life in less than 1 day.

Saliva and blood have a lower concentration of cotinine than urine. The amount of cotinine in your saliva or blood may reach cut-off levels for detection sooner than testing using urine samples.

The exact length of time that cotinine is detectable in your blood may vary depending on your genetic makeup and the amount of nicotine that you were exposed to. Testing with blood may also be less sensitive than testing with urine. This could lead to false negatives or positives.

Nicotine in your blood can be detected using tests that are qualitative (whether or not nicotine is present) and quantitative (how much nicotine is present). These tests can detect nicotine, cotinine, and another breakdown product called anabasine.

Traces of nicotine can generally be found in your hair follicles for up to weeks, months, or even years after your last exposure, according to a 2021 review of literature . This can depend on the hair test administered as well as genetic factors.

But the authors of the review suggest that the results of hair testing may not correlate with blood testing. Hair testing may also show passive or environmental exposure to tobacco smoke.

Although hair testing is possible, it is not used as frequently as urine, saliva, or blood testing.

How long nicotine stays in your system and ways to clear it out more quickly

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• How long nicotine stays in your system depends on factors like how frequently you smoke, your age, and whether you take any medications.
• Nicotine can stay in your blood for about three days, but nicotine can be detected in urine for up to three weeks.
• In addition, nicotine can stay in your hair for about three months, and sometimes up to a year.
• This article was medically reviewed by Jason R. McKnight, MD, MS, a family medicine physician and clinical assistant professor at Texas A&M College of Medicine.

If you’re starting a new job or applying for health insurance, you may be asked to take a nicotine test. Every time you use tobacco, nicotine — a chemical compound found in tobacco — enters your body. It can be detected in the body for up to one year depending on the type of sample a nicotine test uses.

Here is what you need to know about how long nicotine stays in your system and how to clear it out quickly.

How does a nicotine test work?

Nicotine tests collect samples from either the hair, urine, saliva, or blood. Most nicotine tests don’t actually test for nicotine. Instead, they look for one of its by-products: cotinine.

“In the body, nicotine is broken into its derivatives, the most important being cotinine,” says Anis Rehman, MD, an assistant professor in the department of internal medicine at Southern Illinois University. “Cotinine usually lasts much longer than nicotine in the body. Therefore, most smoking tests look for cotinine.”

Nicotine tests are also able to determine if someone is using nicotine replacement therapy versus actively smoking. That’s because it also tests for anabasine, a compound found in tobacco that would not show up from nicotine replacements like patches or gum, says Sharita E. Warfield, MD, a board-certified emergency medicine physician.

And while both nicotine and cotinine can be present in non-smokers if they are around tobacco smoke, the quantity will be significantly lower. “People who are habitual smokers generally have about 30 to 50 ng/ml of nicotine in their blood, whereas non-smokers have less than five ng/ml,” says Warfield.

How long does nicotine stay in your system?

According to Warfield and Rehman, here’s how long nicotine and cotinine can be detected in the body, depending on what sample is being collected:

• Blood: Nicotine can be detected in blood for about three days, and cotinine will last for about ten days.
• Urine: In a regular smoker, nicotine and cotinine can be detected in urine for up to three weeks. In an infrequent user, nicotine only stays in the urine for about four days after smoking, and cotinine lasts for seven to ten days.
• Saliva: Nicotine and cotinine stay in saliva for about four days.
• Hair: Nicotine can stay in the hair for about three months, but can occasionally be detected for up to one year in a consistent smoker.

What factors influence how long nicotine stays in your system?

While tests can give a general idea of how recently you’ve smoked, other factors determine how long nicotine will register in your body.

How frequently you smoke

The most significant determinant of how long nicotine stays in your system is the quantity and frequency you smoke.

“The more a person uses tobacco products, the higher the concentration of nicotine and cotinine,” Warfield says.

Your age

As people get older, their metabolism tends to slow down, and they often become less active. This means the body metabolizes nicotine at a slower rate, so it stays in your system for longer, says Rehman.

Medications

Taking certain medications can change how fast your body processes nicotine. “For instance, antibiotics and phenobarbital [a medicine for controlling seizures] can speed up metabolism, whereas antifungals and some hypertension medications can slow down metabolism,” says Warfield.

A faster metabolism means you’ll flush nicotine out of your system more quickly than if you have a slower metabolism. Speak to your doctor if you are on any specific medications to see how they could impact your body’s ability to clear nicotine.

Hormone levels in your body

Women tend to metabolize nicotine faster than men, says Rehman. “Pregnant women or those on estrogen replacement therapy will clear nicotine faster. as estrogen facilitates nicotine metabolism more quickly,” he says. It is important to note that women who are pregnant should not use tobacco products as they can result in birth defects.

How to clear nicotine from your body

There are a few steps you can take to quickly clear nicotine from your body.

1. Stop smoking

Warfield says abstaining from tobacco products is the best, most direct way to clear nicotine from your system. When you and the people around you stop smoking, the nicotine in your body leaves, and no new quantities of the chemical will enter.

2. Drink water

Drinking more water and other fluids may assist the body in clearing nicotine out, says Rehman. That’s because an increase in urination may help flush out nicotine, and drinking more fluids will cause you to urinate more frequently.

3. Eat a healthy diet

Eating a mix of healthy foods that are high in antioxidants can activate the liver’s functions and help nicotine pass through your body at a faster rate. That’s because these foods boost metabolism, says Warfield.

Try incorporating foods such as:

The bottom line

The length of time nicotine stays in the body depends on what sample is being tested, but usually ranges from a few days to weeks. Cotinine, a derivative of nicotine that is often tested for, stays in your system for a longer period of time. Habits such as eating a healthy diet and drinking more water can help rid the body of nicotine more quickly.

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Sarah Fielding

Sarah Fielding is a freelance writer covering a range of topics with a focus on mental health and women’s issues. She is also the co-founder of Empire Coven, a space for highlighting trailblazing women across New York.

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