About Cotinine Test
Cotinine is a metabolite (byproduct) of nicotine as it is “processed” by the human body. The results are expressed as positive or negative for the presence of cotinine.
Cotinine is an indicator that nicotine has been inhaled or otherwise introduced into the body.
Cotinine levels <10 ng/mL are considered to be consistent with no active smoking.
Values of 10 ng/mL to 100 ng/mL are associated with light smoking or moderate passive exposure, and levels above 300 ng/mL are seen in heavy smokers – more than 20 cigarettes a day.
Nicotine is rapidly metabolized and has a short half-life, but cotinine is metabolized and eliminated at a much lower rate. Because of the resulting increase with time in the cotinine to nicotine ratio in the body, including in the brain, it is of interest to examine the effect of cotinine on nicotine-induced changes.