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 to become cotinine. The amount of cotinine will be proportionate to the amount of nicotine you ingested. These substances are eventually eliminated through your kidneys as urine.
Cotinine, nicotine’s main breakdown product, can usually be detected in your body for up to three months after ingestion. How long it stays in your system will depend on how you ingested the nicotine and how frequently.
Keep reading to learn how long nicotine can be detected in your urine, blood, saliva, and hair.
Nicotine in urine
If you smoke infrequently, cotinine will usually be present in your urine for about four days. With regular exposure to nicotine, cotinine may be detectable for up to three weeks after your last exposure.
A positive urine test depends on when you provide a urine sample relative to the last time you ingested nicotine. If you’re a current smoker, the test may be positive at 1,000 nanograms per milliliter (ng/mL). If you haven’t smoked in over two weeks, a positive test may be over 30 ng/mL. Each lab may have different reference ranges for positivity, so it’s important to discuss the results with your doctor.
Nicotine in blood
Nicotine lasts in your bloodstream for one to three days, and cotinine can be detected in your blood for up to 10 days.
Nicotine in your blood can be detected using tests that are qualitative (whether nicotine is present) and quantitative (how much nicotine is present). These tests can detect nicotine, cotinine, and another breakdown product called anabasine.
False positives for nicotine are common with blood testing. This is usually because of the presence of a compound called thiocyanate. It’s found in foods like broccoli and cabbage and certain medications.
Nicotine in saliva and hair
Nicotine and cotinine can take up to four days to be fully flushed from your saliva.
Traces of nicotine can generally be found in your hair follicles for up to three months after your last exposure. Depending on the hair test used, nicotine may be detected for up to a year after your last exposure.
Although hair testing is possible, it isn’t used as frequently as urine, saliva, or blood testing. That’s because hair testing generally costs more.
Why nicotine lingers
Although there are general guidelines for how long nicotine will stay in your system, this varies from person to person. Depending on your individual circumstances, nicotine may flush from your system sooner or even last longer.
How frequently you smoke
People who smoke are generally divided into three different categories:
- Light users, or people who smoke only once per week
- Moderate users, or people who smoke up to three times per week
- Heavy users, or people who smoke consistently on a daily or weekly basis
If you’re a light user, traces of nicotine are typically cleared from your system within two to three days of smoking.
If you’re a heavy user, traces of nicotine may be detectable for up to a year after your last exposure.
Your lifestyle and genetic makeup
Certain factors can influence how long it takes your body to metabolize nicotine and flush it out.
- Age: The older you are, the longer it can take your body to remove this toxin.
- Genes: Some research suggests that Caucasian and Hispanic people may metabolize nicotine faster than Asian-Americans and African-Americans.
- Hormones: It’s also thought that sex hormones play a role. Women, especially those who are pregnant or taking estrogen, may metabolize nicotine more quickly than men.
- Liver function: Different people may metabolize nicotine at different rates depending on their liver enzymes.
Medications you’re taking
Certain medications can affect how quickly or slowly your body metabolizes nicotine.
Medications that speed up of metabolism of nicotine include:
Medications that slow down metabolism of nicotine include:
- antifungals, like ketoconazole
- high blood pressure medication, such as amlodipine
Clearing nicotine from your body
The best way to clear nicotine out of your system is to abstain from all tobacco products. This way, cells in your body can focus on breaking down nicotine and excreting it.
There are several things you can do to speed up this process:
- Drink water: When you drink more water, more nicotine is released through your body through urine.
- Exercise: This increases your body’s metabolism rate, leading to you to burn up nicotine faster. Sweat released through exercise takes nicotine and its byproducts with it.
- Eat foods rich in antioxidants: Antioxidants can help boost your body’s metabolism rate. Solid options include oranges and carrots. These foods also contain compounds like fiber that aid in toxin removal.
Side effects of nicotine withdrawal
Nicotine is the primary addictive component in cigarettes.
In small doses, nicotine can act as a stimulant, similar to coffee or cocaine. When ingested in larger quantities, nicotine becomes a relaxant. It may decrease tension and anxiety.
Ingesting smaller amounts of nicotine or abstaining entirely can cause symptoms of withdrawal.
- intense tobacco cravings
- increased hunger
- lack of concentration
Your symptoms may be most intense in the first few hours after smoking your last cigarette. These symptoms often lessen in severity after the first three days of being smoke-free.
Your individual symptoms and their potential duration depend on several factors, including:
- how long you’ve been smoking
- the type of tobacco products you used
- how much you smoked on a day-to-day basis
Nicotine replacement therapies (NRTs), such as the patch, can help ease withdrawal symptoms as you decrease the amount of nicotine ingested over time.
Research suggests that using an NRT increases your chances of quitting completely by 50 to 70 percent. If you opt to use an NRT, you’ll still have detectable amounts of nicotine in your body until you cease all nicotine exposure.
If you smoke, traces of nicotine can be found in your hair, blood, urine, and saliva. It can be detected in your saliva for up to four days after your last cigarette and in your hair for up to a year.
The best way to remove nicotine from your body is to stop using tobacco products altogether. You can help speed this process up by:
- drinking water
- eating foods rich in antioxidants, such as oranges