Medically reviewed by Mary Choy, PharmD Key Takeaways Nicotine has a half-life of about two hours and can stay in the blood for about one to three days. Cotinine, a byproduct of nicotine, has a ...

Nicotine itself could clear from your body in a few hours, but its byproduct can linger for days or weeks. Most nicotine tests detect cotinine, which can show up in urine, saliva, blood, hair, and ...