The blood test that detects nicotine is called a cotinine test. It measures recent tobacco use and exposure.

Cotinine is a chemical that comes from the breakdown of nicotine in the body. A blood test for nicotine use or exposure looks for high levels of cotinine.

It can take several days for cotinine to leave your body after you stop smoking. If you need help to quit, you have many options to consider, such as nicotine replacement products and counseling.

Cotinine is detectable in blood, urine, saliva, and hair. If you have to take a cotinine test, you might be asked for a sample of urine or blood. Although urine has higher concentrations of cotinine, blood is sometimes preferred to get an accurate measurement.

A cotinine blood test involves taking a sample of blood from your vein. You might have to go to a clinic or testing center to get the test done. If you are already receiving medical care, a doctor or nurse might take the sample from you in the hospital.

A lab then tests the levels of cotinine in your blood sample.

You do not need to fast or take any other steps in preparation for the test.

You might have to give blood for a nicotine test in many circumstances. Here are some common examples:

  • Medical procedures: Some medical procedures like organ transplants and other kinds of surgery require you to stop smoking. Cotinine testing can confirm smoking cessation.
  • Nicotine poisoning: Cotinine testing can confirm nicotine poisoning, which might happen after accidental ingestion of nicotine gum or other products, especially in children.
  • Employment: Smoking is prohibited in some workplaces. Some employers might have mandatory cotinine testing to confirm employees are tobacco-free.
  • Insurance: You might have to take a nicotine blood test as part of a medical exam to obtain life insurance or health insurance.
  • Smoking cessation programs: A cotinine test can measure compliance with a smoking cessation program. It can also help a doctor to monitor nicotine withdrawal and create a tailored rehabilitation program.

Cotinine levels in blood are measured in nanograms per milliliter (ng/mL).

The following reference values depend on whether you use tobacco or not, with consideration for whether you experience any passive exposure like secondhand smoke:

  • Nontobacco user with no passive exposure: less than 10 ng/mL
  • Nontobacco user with passive exposure: 11 to 30 ng/mL
  • Active tobacco user: may be over 500 ng/mL

The values for a urine cotinine test are different. Levels of cotinine in urine for a nontobacco user are usually less than 10 ng/mL.

Your age, gender, and other health factors can all affect your cotinine levels.

Cotinine levels in your blood, saliva, or urine will be closer to those of a nontobacco user after you have gone 7 to 10 days without smoking.

In one 2020 study, the nicotine and cotinine levels of participants in a quit-smoking program decreased to 1.8% and 3.4%, respectively, just 2 weeks after quitting smoking. After 8 weeks without tobacco, levels were 1.7% and 0.2% of what they were before the stop-smoking program.

If you want to quit smoking, you have many options to explore, including:

  • Counseling: A mental health professional can help you get ready to quit smoking through individual counseling sessions. They can also help you to manage smoking relapse. A doctor might be able to refer you to a counselor or to support groups for people who are quitting smoking.
  • Quit lines: Call 800-QUIT-NOW for telephone counseling to help you stop smoking. You can also call 877-448-7848 for tips to stop smoking. You can call this number 24 hours per day, 7 days per week.
  • Live chat: Livehelp.cancer.gov offers a chat line service where you can speak with a quit-smoking counselor. The chat line is available during certain hours on weekdays.
  • Smoking cessation products: Nicotine replacement products can help you transition off tobacco products. Common options include nicotine patches, gum, lozenges, inhalers, and nasal sprays. A doctor or pharmacist can help you decide if such a product is right for you.
  • Medications: Several prescription medications are available for smoking cessation. A doctor can recommend and prescribe one that might work for you. Examples are bupropion SR (Wellbutrin, Zyban) and varenicline (Chantix).
  • Online resources: The Centers for Disease Control and Prevention (CDC) has several free online resources on its How to Quit Smoking page, including managing withdrawal symptoms and making a quit plan.

A blood test for nicotine looks for high levels of cotinine, which is a chemical made when nicotine breaks down in the body.

It can take 7 to 10 days after you stop smoking for cotinine levels to be about the same as someone who doesn’t use tobacco.