March 5, 2026 · FREED
Whether you are quitting, preparing for a drug test, or just curious — knowing how long nicotine stays in your system helps you understand what your body is going through.
The short answer: nicotine itself is gone within 72 hours. But its metabolites linger longer, and different tests detect different things.
When your body processes nicotine, it converts it into a metabolite called cotinine. Most drug tests actually screen for cotinine because it stays in your system much longer than nicotine itself.
This means nicotine levels drop rapidly, but cotinine can be detected for days or weeks depending on the test.
Blood tests are the most accurate but also the shortest detection window. After 72 hours, most people will test negative for nicotine in blood.
Urine tests are the most common screening method. Heavy vapers or smokers may test positive for up to three weeks after quitting.
Saliva tests are becoming more common in workplace screenings because they are non-invasive and relatively accurate.
Hair tests have the longest detection window but are less commonly used. Nicotine is deposited in hair follicles through the bloodstream and remains as the hair grows.
How much you used. Heavy smokers (20+ cigarettes/day) or frequent vapers will retain cotinine longer than occasional users.
Your metabolism. Faster metabolism clears nicotine more quickly. Age, genetics, and physical activity all play a role.
Hydration. Drinking water helps flush metabolites through your kidneys faster.
Liver function. Nicotine is primarily metabolised in the liver. Healthy liver function speeds up clearance.
Other substances. Certain medications and even foods (like grapefruit) can affect how quickly your body processes nicotine.
For the purposes of quitting, the most important number is 72 hours. This is when nicotine is fully cleared from your bloodstream and the chemical withdrawal peaks. Everything after 72 hours is your body recovering, not withdrawing.
FREED's 3-day free trial is built around this exact window — giving you every tool you need to survive the hardest 72 hours.