What is cotinine?
Cotinine is a metabolite of nicotine, the addictive substance found in tobacco and smoking-cessation products. It is used as a biomarker to indicate whether you have been exposed to nicotine recently.
What does the cotinine test detect?
The more nicotine you have been exposed to, either through consuming products containing nicotine or being exposed to secondhand tobacco smoke, the more cotinine you will have in your body and the higher your levels will be.
What causes high cotinine levels?
Elevated levels of cotinine in your blood may indicate active use of tobacco products, while lower levels may indicate previous use or exposure to secondhand smoke. Your healthcare professional can use the results to test for nicotine poisoning or to prescribe the correct dose of nicotine patches to help you stop smoking. It is also used by insurance companies as part of a health examination before approving a policy.
What is a normal cotinine level?
The following are considered typical blood levels of cotinine¹:
- Active smokers - almost always >10 ng/mL but can be higher than 500 ng/mL
- Nonsmokers - <1 ng/mL, if exposed to typical amounts of secondhand smoke. This can increase to 1–10 ng/mL when exposure is heavy.
What is a high cotinine level?
Any amount greater than 10 ng/mL indicates someone is an active smoker. Levels between 1–10 ng/mL indicate you are exposed to heavy amounts of secondhand smoke.