HOLD guide
Short answer
Nicotine itself clears within 1–3 days. Cotinine, the metabolite tests actually measure, is typically gone from urine in 3–4 days for occasional users but can persist up to 3 weeks in heavy daily users.
General information, not medical advice. Written from published sources, which are listed at the end. It is not a substitute for a doctor, pharmacist or registered dietitian who knows your situation.
In this guide7 sections · 3 min
Two different substances get confused here, and the difference is the whole answer. Nicotine leaves fast. Cotinine — what your body turns nicotine into, and what virtually every test measures — lasts far longer.
The two half-lives
| Half-life | What that means | |
|---|---|---|
| Nicotine | ~1–2 hours | Half is gone within a couple of hours; effectively cleared in 1–3 days. |
| Cotinine | ~16 hours | Roughly ten times more persistent. This is why tests look for it. |
A half-life is the time to clear half of what is present, so full clearance takes roughly five of them. For nicotine that is under half a day; for cotinine, around three to four days — longer still if you were using heavily, because you started from a higher level.
What is actually happening in your liver
Most of the nicotine you take in is converted to cotinine by a liver enzyme called CYP2A6. That single enzyme is the bottleneck, and it is the reason the ranges in every table below are so wide.
CYP2A6 activity varies substantially between people for genetic reasons. Fast metabolisers clear nicotine quickly; slow metabolisers hold onto it much longer. This is not a lifestyle variable you can influence, and it is a bigger source of variation than anything you could do differently.
Detection times by test
| Test | Occasional use | Heavy daily use |
|---|---|---|
| Blood | 1–3 days | Up to 10 days |
| Urine | 3–4 days | Up to 3 weeks |
| Saliva | 1–4 days | Up to 7 days |
| Hair | 1–3 months | Up to 12 months |
What changes your number
- How much and how long. Years of heavy use leave more cotinine to clear than a fortnight of occasional vaping.
- Genetics. CYP2A6 activity varies a lot between people, and it is the single largest individual difference.
- Age. Clearance slows somewhat with age.
- Sex and hormones. Nicotine metabolism is faster in women than men on average, faster again during pregnancy, and faster with oestrogen-containing hormone preparations.
- Kidney and liver function. Both affect how quickly it leaves.
- Other medications and diet, which can induce or inhibit the same enzyme.
- Menthol. There is evidence it slows nicotine metabolism modestly.
There is no single pass mark
Worth understanding before you plan around a date. A cotinine test does not return "positive" or "negative" in an absolute sense — it returns a concentration, which is compared against whatever threshold that testing body has chosen.
Thresholds differ between insurers, employers and clinical settings, and some are set to distinguish active use from second-hand exposure while others are not. So two people with identical cotinine levels can get different results from different tests. If the outcome matters, ask which test and which cut-off, rather than relying on a general timeline.
The same applies to NRT. Patches, gum and lozenges all produce cotinine, so they register like any other nicotine source. Declare them rather than assuming medical use is treated differently.
Detox is not the same as recovery
This is the part worth being clear about. Nicotine being gone from your blood does not mean withdrawal is over. The chemical clears in days; the adjustment takes weeks, because withdrawal comes from your brain readjusting rather than from nicotine still circulating.
So being "clean" on a test at day four while still feeling terrible is completely normal, and is not a sign anything has gone wrong. Cravings peak around day 3 and fade over three to four weeks — well after the last trace of nicotine has gone.
Can you speed it up?
Not in any way that matters. Staying hydrated, sleeping and exercising support normal function, but clearance is governed by liver enzyme activity, which you cannot meaningfully hurry. Products marketed as nicotine detox kits have no good evidence behind them and are not worth the money.
The only variable you control is the date of your last exposure.
