Nicotine Metabolite Blood Test in California

What this test measures

Nicotine is the addictive substance in tobacco, and the body converts it into several metabolites. The most studied is cotinine, which has a longer half-life than nicotine and is therefore easier to detect. Measuring cotinine in blood gives an indication of recent nicotine exposure from cigarettes, cigars, smokeless tobacco, or nicotine replacement products. It does not distinguish the source of nicotine by itself.

The test uses a blood sample and reports cotinine along with related metabolites such as nicotine and trans-3-hydroxycotinine when the laboratory measures them. Cotinine can also be measured in urine or saliva, but blood testing offers a direct measurement at the time of collection. Detection windows depend on how much nicotine was used and how frequently.

Results reflect exposure, not addiction or intent. A detectable level shows that nicotine entered the body recently, whether from tobacco, an e-cigarette, or a cessation product. Very heavy passive exposure can raise cotinine in some settings, though usually to lower levels. A qualified healthcare provider interprets the result in the appropriate context.