How long is nicotine detectable in blood?

How long is nicotine detectable in blood? Nicotine itself leaves the blood quickly. Its half-life is about 2 hours, so most of the nicotine is gone within one day after the last use. Blood tests therefore usually look for cotinine, the main breakdown product of nicotine. Cotinine stays in the blood much longer: after occasional use, a test can usually detect it for about 1 to 4 days, and after regular daily use for up to about a week, in slow metabolisers longer.

The exact time depends on the amount of nicotine, on the test method and on individual factors. The sections below explain how nicotine is broken down, which values a laboratory uses, and why the same pouch or cigarette can show up for a different number of days in two different people.

Nicotine and cotinine: two substances, two half-lives

After a cigarette or a nicotine pouch, nicotine enters the blood within seconds or minutes. The liver then breaks down most of the nicotine, mainly with the enzyme CYP2A6. About 70 to 80 percent of the nicotine becomes cotinine (Hukkanen, Jacob & Benowitz, 2005).

The two substances have very different half-lives. The half-life is the time in which the level in the blood falls by half.

After about five half-lives, only around 3 percent of the original level remains. For nicotine, this point is reached after about 10 hours. For cotinine, it takes about 3 to 4 days. Sensitive laboratory methods can still measure very small amounts after this time. This is the reason why regular users can test positive for cotinine for more than a week.

Nicotine detection times in blood, urine, saliva and hair

Blood is only one of several materials that a laboratory can test. The following times are typical values after the last use of nicotine. They are guide values and not guarantees.

Urine tests often detect nicotine use for longer than blood tests. The concentration of cotinine in urine is several times higher than in blood, so the value stays above the cut-off for more days. Hair tests show use over a longer period, because nicotine and cotinine are stored in the growing hair. However, hair tests are rare in daily practice.

Which nicotine blood values count as positive?

A laboratory does not only answer "yes" or "no". It measures the amount of cotinine and compares it with a cut-off value. The Society for Research on Nicotine and Tobacco (SRNT) published recommended cut-offs for the verification of tobacco use (Benowitz et al., 2020):

• Blood (plasma or serum): 3 to 10 ng/ml of cotinine, with 3 ng/ml as the recommended value
• Saliva: 3 to 10 ng/ml of cotinine
• Urine: 30 to 50 ng/ml of cotinine

Older studies and many laboratories still use higher cut-offs, for example 10 to 15 ng/ml in blood. A higher cut-off means that a test becomes negative earlier after the last use. For comparison: people who use nicotine every day often have blood cotinine levels of about 100 to 250 ng/ml. People who do not use nicotine, but who are exposed to second-hand smoke, usually have values below 1 to 3 ng/ml.

Why the time differs from person to person

The breakdown of nicotine is very individual. Two people who use the same product in the same amount can have clearly different detection times. The most important factors are:

• Daily amount: The more nicotine a person takes in each day, the higher the cotinine level is at the start. A higher start level needs more time to fall below the cut-off.
• Duration of use: After years of regular use, the cotinine level is stable and high. After a single pouch or cigarette, the level is low and falls below the cut-off quickly.
• Genetics: Variants of the enzyme CYP2A6 make some people fast metabolisers and other people slow metabolisers. Slow metabolisers keep cotinine in the blood for longer. These variants are more common in some populations, for example in parts of East Asia.
• Sex and hormones: On average, women break down nicotine faster than men. The contraceptive pill and pregnancy make the breakdown even faster (Benowitz et al., 2006).
• Liver and kidney function: Diseases of the liver slow down the breakdown. Reduced kidney function slows down the removal of cotinine from the body.
• Age: In older people, the breakdown of nicotine is often slower.

Pouches, snus, vapes and cigarettes in a cotinine test

For a blood test, the source of the nicotine does not matter. Cigarettes, nicotine pouches, snus, e-cigarettes, nicotine gum and nicotine patches all lead to cotinine in the blood. A cotinine test therefore cannot show whether a person smoked or used a pouch.

The level depends on the daily amount of nicotine. Strong nicotine pouches can deliver as much nicotine to the blood as a cigarette. More details about the nicotine content of different products are available in our article how much nicotine is in a cigarette. People who use several strong pouches per day should expect cotinine levels that are similar to the levels of smokers.

Some tests can separate tobacco use from pure nicotine. These tests look for anabasine, a substance that occurs in tobacco but not in medical nicotine products. Tobacco-free pouches contain purified nicotine. For this reason, they usually lead to low anabasine values. However, the amount of anabasine depends on the purity of the nicotine, so a negative result is not guaranteed. Tests for carbon monoxide in the breath only show smoking. A pouch does not increase carbon monoxide.

Can nicotine leave the blood faster?

There is no proven method that removes nicotine or cotinine from the blood much faster. Many websites recommend water, sport, sauna or special detox drinks. Water and sport do not change the breakdown of nicotine in the liver. More water can dilute urine, but laboratories check urine for dilution, and blood values do not change.

The only factor that reliably lowers the cotinine level is time without nicotine. After regular use, this takes about a week for blood and longer for urine. Our article with tips for snus withdrawal describes possible withdrawal symptoms.

When cotinine tests are used

Typical situations in which a laboratory measures cotinine are:

• Life insurance and health insurance: In some countries, insurance companies test for cotinine to decide between non-smoker and smoker rates. Many insurers count nicotine pouches as nicotine use, and applicants must answer the questions about nicotine truthfully.
• Surgery: Some clinics test cotinine before plastic surgery or other planned operations and require a period without nicotine.
• Transplant programmes and some medical treatments: Some programmes require a period without nicotine.
• Studies and quit programmes: Researchers use cotinine to check whether participants use nicotine.

A standard drug test for illegal substances does not include nicotine. Cotinine is only measured when the test specifically asks for it.

What this means for pouch users

If you use nicotine pouches and want to reduce your daily nicotine amount, the strength of the pouch is the most important factor. The nicotine calculator compares strengths in mg per pouch, the light nicotine pouches collection lists the products with the lowest nicotine content, and nicotine-free pouches do not lead to cotinine in the blood.

Sources

• Benowitz, N. L., Bernert, J. T., Foulds, J., et al. (2020). Biochemical verification of tobacco use and abstinence: 2019 update. Nicotine & Tobacco Research, 22(7), 1086 to 1097. doi.org/10.1093/ntr/ntz132
• Benowitz, N. L., Hukkanen, J., & Jacob, P. (2009). Nicotine chemistry, metabolism, kinetics and biomarkers. Handbook of Experimental Pharmacology, 192, 29 to 60. doi.org/10.1007/978-3-540-69248-5_2
• Benowitz, N. L., Lessov-Schlaggar, C. N., Swan, G. E., & Jacob, P. (2006). Female sex and oral contraceptive use accelerate nicotine metabolism. Clinical Pharmacology & Therapeutics, 79(5), 480 to 488. doi.org/10.1016/j.clpt.2006.01.008
• Hukkanen, J., Jacob, P., & Benowitz, N. L. (2005). Metabolism and disposition kinetics of nicotine. Pharmacological Reviews, 57(1), 79 to 115. doi.org/10.1124/pr.57.1.3

About this article. This article provides general information and is not medical advice. Detection times are guide values and depend on the individual person and on the laboratory. Nicotine is an addictive substance. Nicotine pouches are not medicines and are not a treatment for nicotine dependence. If you want to reduce or end your nicotine use, or if you have a health condition, please speak to your doctor or a pharmacist. Sale to adults aged 18 and over only.

For adults 18+ only. Nicotine is an addictive substance. We sell the products mentioned in our guides. Our editorial content is written independently.