7 doctors weighed in:
How long does it take for nicotine to leave your body (urine and blood stream) after you've stop smoking?
7 doctors weighed in

Dr. Jon Ahrendsen
Family Medicine
5 doctors agree
In brief: It varies
Nicotine metabolism is complex.
Most nicotine is metabolized in the body to co-nicotine, and this is what is tested for. Nictotine is 1/2 gone after 2 hours, co-nicotine about 20. It takes about 5 1/2 lives for a drug to be "97% gone". 10 half lives for 99.9% another source says a urine test can be positive 7 to 20 days after smoking.

In brief: It varies
Nicotine metabolism is complex.
Most nicotine is metabolized in the body to co-nicotine, and this is what is tested for. Nictotine is 1/2 gone after 2 hours, co-nicotine about 20. It takes about 5 1/2 lives for a drug to be "97% gone". 10 half lives for 99.9% another source says a urine test can be positive 7 to 20 days after smoking.
Dr. Jon Ahrendsen
Dr. Jon Ahrendsen
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Dr. Alan Wartenberg
Addiction Medicine
In brief: 24-48 hours
Nicotine is a very short-acting drug and is metabolized quickly, which is why people who smoke have a cigarette generally at least once every 45 minutes while awake.
However, its metabolite cotinine lasts longer, and can be detected for about 2 days after quitting smoking. It depends to some extent on whether you are a half-pack/day or a 3-pack/day person, but usually 48 hours is adequate.

In brief: 24-48 hours
Nicotine is a very short-acting drug and is metabolized quickly, which is why people who smoke have a cigarette generally at least once every 45 minutes while awake.
However, its metabolite cotinine lasts longer, and can be detected for about 2 days after quitting smoking. It depends to some extent on whether you are a half-pack/day or a 3-pack/day person, but usually 48 hours is adequate.
Dr. Alan Wartenberg
Dr. Alan Wartenberg
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