How Long Does Nicotine Stay in Your System?

Quick Answer

Nicotine has a short half-life of about 2 hours and clears from the blood within 1–3 days. However, drug tests measure cotinine, a metabolite that lasts much longer. Cotinine is detectable in blood for 1–10 days, urine for 3–4 days (up to 3 weeks in heavy users), and hair for up to 90 days.

Detection Windows by Test Type

Blood Test

• Nicotine: 1–3 days
• Cotinine: 1–10 days
• Most accurate for recent tobacco use

Urine Test (Most Common)

• Occasional smoker: 3–4 days
• Regular smoker: 7–14 days
• Heavy/long-term smoker: up to 21 days
• Standard cutoff: 200 ng/mL cotinine

Saliva Test

• Detection window: 1–4 days
• Becoming more common for insurance screenings
• Cutoff: 10–30 ng/mL cotinine

Hair Follicle Test

• Detection window: up to 90 days
• Can detect patterns of regular use
• Less reliable for infrequent or secondhand exposure

Nicotine vs. Cotinine

Nicotine itself is metabolized quickly — within 2 hours, half of it has been converted by the liver into cotinine. Cotinine has a much longer half-life of 16–20 hours, which is why it's the preferred marker for testing. About 70–80% of nicotine is converted to cotinine.

Factors That Affect Clearance Time

Frequency and duration of use — the more and longer you've smoked, the more nicotine and cotinine have accumulated. A pack-a-day smoker for 20 years will take much longer to clear than someone who smoked for a few months.

Age — older adults metabolize nicotine more slowly due to reduced blood flow to the liver.

Hormones — estrogen speeds up nicotine metabolism. Women, especially those on birth control or who are pregnant, metabolize nicotine faster.

Liver function — since the liver converts nicotine to cotinine, liver health directly affects processing time.

Kidney function — cotinine is eliminated through the kidneys. Impaired kidney function extends detection time.

Genetics — variations in the CYP2A6 enzyme affect metabolism speed. Some people are naturally fast or slow metabolizers.

Type of tobacco product — cigarettes, vaping, chewing tobacco, and patches deliver different nicotine amounts and at different rates.

Nicotine Clearance Timeline After Quitting

Timeframe	What Happens
2 hours	Half of nicotine metabolized
1–3 days	Nicotine undetectable in blood
3–4 days	Cotinine clears (light smokers)
1–3 weeks	Cotinine clears (heavy smokers)
2–4 weeks	Most withdrawal symptoms subside
90 days	Hair test window closes

Why It Matters

Nicotine testing is commonly used for:

• Life and health insurance — smokers pay significantly higher premiums
• Employment screening — some employers (especially healthcare) test for tobacco
• Surgery preparation — surgeons may require nicotine-free status before elective procedures
• Smoking cessation programs — to verify abstinence