Cocaine, MDMA, amphetamine and ketamine are typically detectable in urine for 1 to 4 days after a single use. THC stays visible for 3 to 30 days, depending on how often someone uses. Hair analysis stretches that window to about 90 days. Below you will find detection times per substance and per matrix, with the cut-off values labs test against.
Most people looking this up have a test date in sight: a job application, a driving-licence assessment, a workplace check, or personal certainty. Preparing starts with knowing what a lab actually measures.
How long do drugs stay detectable in urine, blood, hair and saliva?
Detection windows vary sharply by matrix. Urine is the standard medium for most workplace and licensing tests. Blood shows recent use (hours to days). Hair records use over the past 90 days. Saliva captures use in the last 1 to 2 days.
The table below summarises typical windows, with the SAMHSA urine-screening cut-off per substance.
| Substance | Urine (single use) | Urine (chronic) | Blood | Hair | Saliva | Urine cut-off (ng/mL) |
|---|---|---|---|---|---|---|
| Cocaine (benzoylecgonine) | 2 to 4 days | up to 10 days | up to 24 hours | up to 90 days | 1 to 2 days | 150 |
| Amphetamine | 1 to 3 days | up to 7 days | up to 24 hours | up to 90 days | 1 to 2 days | 500 |
| MDMA | 2 to 4 days | up to 5 days | up to 24 hours | up to 90 days | 1 to 2 days | 500 |
| Methamphetamine | 3 to 5 days | up to 7 days | 1 to 3 days | up to 90 days | 1 to 2 days | 500 |
| Ketamine | 2 to 4 days | up to 7 days | up to 24 hours | up to 90 days | 1 to 2 days | 50 to 100 |
| GHB | 6 to 12 hours | up to 12 hours | up to 6 hours | hard to measure | up to 6 hours | 10 mg/L (blood) |
| Opiates (morphine, codeine) | 2 to 4 days | up to 7 days | up to 24 hours | up to 90 days | 1 to 2 days | 2000 |
| Benzodiazepines | 3 to 7 days | up to 30 days | 1 to 3 days | up to 90 days | 1 to 2 days | 200 to 300 |
| Cannabis (THC-COOH) | 3 to 7 days | 10 to 30 days | up to 24 hours (THC), 7 days (metabolite) | up to 90 days | 1 to 2 days | 50 |
These numbers are guidelines at average use. Individual outliers do occur.
What determines how long a substance stays detectable?
Five variables explain almost all the difference between people who used the same amount.
Frequency of use. In chronic use, especially with cannabis, the lipid-soluble metabolite THC-COOH accumulates in fat tissue. That window can extend to 30 days or longer.
Dose. Higher doses shift detection time by hours to days. With long-half-life benzodiazepines like diazepam, that can stretch into weeks.
Metabolism and body fat. Fat-soluble substances like THC linger longer with higher fat mass. Cocaine, which clears quickly into benzoylecgonine, is less sensitive to this.
Hydration and urine pH. Drinking heavily dilutes urine and can push concentration below the cut-off. Labs correct for this with creatinine measurement. Dilute too far and you get a "diluted" or "invalid" result, not a negative.
Individual clearance. Liver and kidney function vary between people. Reduced liver function generally extends the detection window.
Which matrix should you choose: urine, blood, hair or saliva?
The right choice depends on the time window you need to cover and the context of the test.
- Urine is the standard for workplace checks and driving-licence assessments. Detection window: days, or with cannabis, weeks. See our 5-panel or 10-panel for the standard urine tests.
- Blood shows recent use (hours to 1 or 3 days) and is common in driving fitness or forensic contexts.
- Hair records use over roughly the past 90 days. Useful for longer-range investigations, such as custody cases or progress monitoring.
- Saliva covers the last 1 to 2 days. Dutch police use saliva tests at the roadside for speed and non-invasiveness.
If in doubt: for a job application or workplace check, urine works for most employers. For a longer look-back period, hair is more sensitive.
Cut-off, screening and confirmation: how a lab decides
A drug test runs in two stages. The first is an immunoassay screening: fast, cheap, with a threshold (cut-off) below which a result reads negative. For cocaine in urine that is 150 ng/mL of benzoylecgonine. For THC metabolite it is 50 ng/mL.
A positive screening is confirmed with GC-MS or LC-MS/MS. The confirmation test measures the exact molecule and uses a lower threshold: 100 ng/mL for cocaine, 15 ng/mL for THC-COOH.
"Below the cut-off" does not mean "drug-free". It means the concentration sits below the agreed threshold for that specific test.
Can a drug test give a false positive?
Yes, and the well-known examples come back every year. Poppy seeds (in poppy-seed rolls) can push opiates above the old 300 ng/mL cut-off; the SAMHSA threshold was raised to 2000 ng/mL in 1998 for that reason. Pseudoephedrine in nasal spray can trigger an amphetamine screening. CBD products with trace THC can produce a positive THC screen at higher doses.
A confirmation test with GC-MS or LC-MS/MS resolves nearly all false positives by identifying the exact molecule.
Workplace drug testing: what is allowed, what should you know?
In the Netherlands, workplace drug testing is bound by conditions. The employer must demonstrate a legitimate interest (safety in driving roles, machine work, or security), a testing policy must exist with works-council approval, and GDPR demands the least-intrusive method.
You may refuse a test. The employer may attach consequences within the bounds of the testing policy and labour law. Ask for the policy in writing for your own records.
A test at an accredited lab is legally stronger than an on-site rapid test. Our 5-panel and 10-panel are analysed at an ISO-accredited laboratory.
5-panel or 10-panel: which should you choose?
A 5-panel test screens for the five most common substances: cocaine, amphetamines (including MDMA), opiates, cannabis and methamphetamine. Enough for most employer checks.
A 10-panel extends this with benzodiazepines, barbiturates, methadone, propoxyphene and MDA. Suitable for broader screening, custody matters, or contexts where prescription medication is relevant.
Want to rule out one specific substance? See the standalone cocaine screening, ketamine screening or amphetamine screening. For alcohol use over weeks, the CDT test is the standard choice.
Frequently asked questions
How long does cocaine stay in urine? 2 to 4 days after a single use, measured as the metabolite benzoylecgonine at a cut-off of 150 ng/mL.
How long does cannabis stay in urine? 3 to 7 days at single use; 10 to 30 days at daily use because of storage in fat tissue.
How long does GHB stay detectable? 6 to 12 hours in urine. One of the shortest detection windows of any common substance.
How long does MDMA stay in urine? 2 to 4 days after a single use, at a cut-off of 500 ng/mL.
Can an employer require me to take a drug test? Not without an approved testing policy, a legitimate interest and works-council consent. Ask for the policy in writing.
What is a false positive? A screening that reads positive because of cross-reactivity with another substance. A GC-MS confirmation almost always corrects this.
What you can do next
Choose the test that fits your situation. For job applications and standard workplace checks, our 5-panel urine test is enough. For a broader spectrum, the 10-panel is the standard choice. For targeted questions about one substance, choose the matching standalone screening.
References
- SAMHSA. Mandatory Guidelines for Federal Workplace Drug Testing Programs. 2017. samhsa.gov
- RIVM / Trimbos Institute. National Drug Monitor. 2024. rivm.nl
- Huestis MA. Human Cannabinoid Pharmacokinetics. Chem Biodivers. 2007;4(8):1770-1804. PMID: 17712819.
- Verstraete AG. Detection times of drugs of abuse in blood, urine, and oral fluid. Ther Drug Monit. 2004;26(2):200-205. PMID: 15228165.
- European Monitoring Centre for Drugs and Drug Addiction (EMCDDA). DRUID project. 2012.
Disclaimer
This article provides general information about substance detection windows and is not medical advice. For health questions, contact your GP or occupational physician. A drug test at Zuivertest is not a forensic statement; consult the requesting authority for legal contexts.
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