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.
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.
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.