- 1 What is Nicotine?
- 2 Effects of Nicotine in the Body
- 3 Nicotine Addiction
- 4 Nicotine Drug Test
- 5 Nicotine Blood Test
- 6 Nicotine Urine Test
- 7 Nicotine Saliva Test
- 8 How to Effectively Clear Nicotine From the Body?
What is Nicotine?
When one hears of nicotine, tobacco immediately comes into mind. Nicotine was named after the tobacco plant, Nicotania tabacum, which, in turn, was named after French Jean Nicot de Villemain, who sent and promoted the plant in Paris during the 16th century.
This alkaloid constitutes approximately 3% of tobacco’s total dry weight, mostly its roots and leaves. However, smaller amounts (around 2-7µg/kg) can also be found among other species of the nightshade family of plants (Solanaceae), such as tomatoes, potatoes, eggplants, green peppers and leaves of coca plants. [1, 2]
In the late 17th century, nicotine was used as an insecticide. It has an antiherbivore effect, particularly lethal to insects. Its potent nervous system effects deterrent to insects, are similar to those attracting humans, inducing addiction.
Nicotine sulfate was considered to be the most hazardous botanical insecticide available to home gardeners, since it was highly toxic to humans and was rapidly absorbed through the skin. Thus, in 2008, the United States Environmental Protection Agency (EPA) prohibited the use of these nicotine-based pesticides. [3, 4, 5]
Effects of Nicotine in the Body
In high concentrations (30-60mg), nicotine is neurotoxic, deterrent to insects and lethal to humans. On the other hand, in smaller doses (1 mg in every cigarette stick), it acts as a stimulant. 
Affecting mostly the nervous system, nicotine decreases the appetite, boosts mood, relieves depression, enhances brain activity, and improves cognition and memory. However, it also stimulates intestinal motility, increases salivation, increases both the heart rate and blood pressure, and may even cause nausea and vomiting. 
It only takes one milligram of nicotine per one cigarette stick to stimulate the brain, but this would be enough to cause cigarette smoking-induced nicotine addiction. 
The brain creates neurotransmitters, substances which can determine sensations and emotions. When nicotine is inhaled, it then masks such neurotransmitters, deceiving neurons and replacing the substance, acetylcholine on its receptors. It then causes an abnormal production of dopamine, inducing euphoria. [9, 10]
After smoking, the nicotine effect ceases and the euphoria disappears. Thus, when the feel-good sensation is gone, there may be an attempt to recover such feeling; hence, the need for another bout of cigarette smoking. The cycle and, subsequently, addiction then ensues. 
An illustration describing how nicotine stimulates the brain, leading to addiction.
Some smokers may even attempt to quit, and experience symptoms of nicotine withdrawal: intense craving for nicotine, anxiety, depression, drowsiness, trouble sleeping, frustration, headaches, weight gain and inability to concentrate. These symptoms peak about 2 to 3 days after cessation.
They seem to be more frequent among people who had longer years of smoking and who have had more cigarettes sticks smoked per day. These are the same symptoms the nicotine addicts are avoiding, thus prolonging their addiction to smoking and to nicotine. [9, 11]
Nicotine Drug Test
Nicotine use may not only be proven based on one’s symptoms, a number of diagnostics are now available to detect nicotine in the body.
When one smokes, nicotine inhaled is then metabolized into cotinine in organs such as the lungs and the liver, and subsequently excreted in the urine. Aside from nicotine, cotinine is a reliable biomarker and indicator for nicotine use, detectable in the blood, urine, and saliva. 
How Long Does Nicotine Stay in your System?
The length of time that nicotine stays in the body and cotinine can be a reliable indicator of nicotine use depends on the amount of tobacco smoked, the number of years smoking tobacco, and the type of nicotine test performed. It can be as short as 2 days, or as long as 3 months. 
Nicotine Blood Test
Both qualitative and quantitative blood tests can be used to detect nicotine use. Either blood nicotine levels or its presence or absence can be determined. Nicotine, along with its derivatives cotinine and anabasine, can be used for these blood tests. These tests can detect even the slightest traces of nicotine in the bloodstream. 
How Long Does Nicotine Stay in your Blood
Nicotine is metabolized into cotinine, which then admixes with blood. Liver detoxification then takes place, facilitating removal of toxins from the blood. This process is slow in comparison to the removal of waste products by the kidney in form of urine, which takes place at a faster rate. [14, 15]
In these blood tests, nicotine is visible usually 1 to 3 days after last use of a nicotine-containing product, such as cigarettes, smokeless tobacco (snuff), and nicotine patches or gum. This may also vary in lieu of the amount of nicotine use, and the individual’s health and age. 
On the other hand, when cotinine levels are used for determination, it may take 1 to 10 days until the levels will be undetectable in the blood. 
However, a number of reasons can lead to false positive results of nicotine in the blood. These include working at metal refining areas where high levels of thiocyanate present, consumption of thiocyanate containing foods like cabbage, broccoli, almonds and mustards, and intake of medications such as amphetamines. Laboratory errors should also be considered. [16, 17]
An image showing how a nicotine blood test is done.
Nicotine Urine Test
The standard test for determining nicotine use is thru a urine sample. The test is the most commonly used one, since it is readily available, and is sold over the counter. It detects cotinine, the nicotinine metabolite also used in blood tests. 
In this test, a urine sample is collected, in which a strip is dipped for 5 minutes. The result is then read as either positive or negative. The accepted standard cutoff level of 200 ng/ml of nicotine is the test’s basis. 
How Long Does Nicotine Stay in your Urine?
When inhaled, nicotine is converted into cotinine, which together with the body’s wastes products is excreted in the urine. In detecting nicotine and its metabolites in the body, levels remain detectable in the urine only for 3 to 4 days. [8,18]
However, this may be different for some cases. For passive smokers, urine nicotine test can be positive for as long as 15 to 20 days. Cotinine may also take longer to be excreted with wastes if menthol cigarettes are used. 
An illustration of a urine cotinine test.
Nicotine Saliva Test
This is said to be the most accurate nicotine test and is most preferred. It does not only eliminate the need to handle urine specimens, but it can also provide an approximate amount of tobacco used by the person. It can detect levels 0 to 2,000 ng/ml of nicotine, a range lower than that can be determined by the urine test. [20, 21]
In this test, a person must provide a saliva sample, in which a strip is soaked for 20 minutes. The saliva then reacts with cotinine, indicating different levels of cotinine and suggesting the amount of nicotine exposure. 
How Long Does Nicotine Stay in your Saliva?
Cotinine, the nicotine metabolite used in the saliva test, has a longer half life than nicotine itself. It can be detected in the saliva more than 10 hours, even as long as 2 to 4 days. 
Equipment used for nicotine saliva test.
How to Effectively Clear Nicotine From the Body?
Nicotine is a stimulant and is highly addictive. But even in the presence of withdrawal symptoms, quitting can be feasible. The following are means with which nicotine can be cleared off from the body, and in the process, avoid nicotine withdrawal syndrome effectively: 
- Plenty of water must be consumed. The more water consumed, the more nicotine released from the body thru the urine.
- Eat fruits and vegetables. They are antioxidants, with high fiber and water content. They can help metabolize the nicotine out of the system.
- Exercise. It improves circulation and enables the body to release toxins thru sweat, making nicotine removal faster.
- Eat foods such as garlic, onions and egg yolks. These increase bile production in the liver, helpful in toxin and nicotine removal.
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- Henningfield, JE. Nicotine Psychopharmacology Research Contributions to United States and Global Tobacco Regulation: A Look Back and A Look Forward. Psychopharmacology. 184 (3-4); 286-91.
- Rodgman, A/ et al. The Chemical Components of Tobacco and Tobacco Smoke. Boca Raton, FL, 2009. CRC Press.
- USEPA (29 Oct 2008). Nicotine : Notice of Receipt of Request to Voluntarily Cancel a Pesticide Registration. Federal Register. 64320-64322.
- Geick, M. et al. Pesticide: Natural Isn’t Always Best. Colorado State University Extension, Denver. 2010.
- George, TP. Et al. Nicotine and Tobacco. In: Goldman L, et al. Cecil Medicine. 24th ed. Philadelphia, PA. Saunders Elsevier; 2011: 31.
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- Benowitz, N.L, et al. Nicotine Chemistry, Metabolism, Kinetics and Biomarkers. Handbook of Experimental Pharmacology. 2009; 192: 29-60.
- Dhar, P. Measuring Tobacco Smoke Exposure: Quantifying Nicotine/ Cotinine Concentration in Biological Samples By Colorimetry, Chromatography and Immunoassay Methods. Journal of Pharm Biomed Anal. 2004. 25(1): 155-68.
- De Leon J, et al. Total Cotinine in Plasma: A Stable Biomarker For Exposure to Tobacco Smoke. Journal of Clinical Psychopharmacology. 2002 Oct; 22 (5): 496-501.
- Hecht, ss, et al. Effects of Watercress Consumption On Urinary Metabolites of Nicotine in Smokers. Cancer Epidemiology Biomarkers Prev. 199 Oct; 8(10): 907-13.
- Benowitz, NL. Et al. Mentholated Cigarette Smoking Inhibits Nicotine Metabolism. Journal of Pharmacological Experimental Therapeutics, 2004Spe; 310(3): 1208-15.
- Etter, JF. Et al. Saliva Cotinine Levels in Smokers and Nonsmokers. American Journal of Epidemiology. 2000; 151 (3)
- Croswell, J. How To Clear Nicotine From Your System. www.livestrong.com, 2010 Sep.