Drug Test Detection Times & Cut Off Levels

Reviewed by Dr Michael Garside and Dr Kate Garside, directors of UK Drug Testing. Last updated October 2026.

On this page: Urine detection times · Saliva detection times · Detection time calculator · Which test to use · FAQs

Drug test detection times and cut off levels for urine and saliva drug testing kits

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Detection times for drugs

The time that drugs can be detected on a drug test, varies depending on the type of drug test kit used, and also the brand of drug testing kit that is used. This is often referred to as the window of detection for a drug. As a general rule drugs can be detected longer in urine than in saliva.

Drug detection windows by test type

The scale stretches the shorter times so hours and months fit on one chart. Urine can reach 45 days after heavy long-term cannabis use (lighter bar). Windows vary by drug, dose, frequency of use and test cut-off.

Urine vs saliva detection times for common drugs

Longest typical window at standard cut-off levels. Lighter bars show longer windows after heavy use: cannabis up to 45 days, long-acting benzodiazepines up to 6 weeks.

Urine drug test detection times & cut off levels

Use the tables below to confirm the sensitivity and window of detection possible. Our urine drug testing cup kits contain everything you need to perform urine drug screening in the workplace.

A drug test cut-off level is the concentration at which a screening drug test is designed to report a positive result. A test with a lower cut-off level may detect smaller concentrations of a substance or its metabolites, potentially extending the detection window. The actual detection period depends on the substance, sample type, test method and individual circumstances. Cut-off levels vary between drug tests, so always check the specifications of the test being used.

Drug test detection times and drug test detection cut off level table below shows:

• The full name of drug
• Drug test code abbreviations on the drug test next to its name
• The detection windows for each drug i.e. the approximate detectable time each drug remains detectable in the urine after last use
• The cut off levels for detection of each drug in urine

These tables below should help you in understanding what the abbreviated names on a drug test mean, and how long after a drug has been consumed can the drug be detected in urine or saliva.

UK Drug Testing urine drug test codes & standard sensitivity cut off levels and detection times

Some ultra sensitive drug test membranes now have enhanced sensitivities specified in the individual drug test listing. Ultra drug tests may not extend the detection period by a whole day, explaining why the detection window is quoted as the same as the less sensitive option. But you will get a positive result at the lower cut off levels quoted.

* Cannabis THC detection times in urine have been reported as testing positive up to 45 days after last use following heavy long term Cannabis use in individuals with high residual body fat levels, as THC is stored in fat and can be released gradually. This is particularly common if an ultra sensitive 20ng or 25ng THC detection urine drug test is used in place of the usual 50ng THC detection test. How long THC stays in a person's system varies hugely between individuals.

Browse our urine drug test kits, from single-drug strips to 23-panel cups, or ultra sensitive drug tests that detect at the lower cut-off levels shown above.

How long are drugs detectable in urine and saliva?

Cut-off levels for drug test kits are brand specific and as a guide, the window period for drug detection using a saliva or oral fluid drug testing kit are shorter than the comparable urine drug test.

The length of time a drug can be detected on any drug test will vary from individual to individual, and will also depend on the drug test brand, the sensitivity of the drug test, as well as the format of the drug test kit being used.

The amount of time drugs stay in the body and can be detected on a drug test depends on many factors such as:

• The amount of the drug that has been taken
• The strength and purity of the drug taken
• The body weight of the person being drug tested
• The rate of metabolism of the individual being tested
• Whether the person being tested is a casual drug user or a long-term user.
• Cut-offs are brand specific and as a guide, the window period for drug detection using saliva or oral fluid drug test are shorter than the comparable urine test.

Oral fluid saliva drug test kit detection times

Oral saliva drug test detection times tend to be shorter, when compared to the equivalent detection times in a urine drug test. This can be useful particularly for employers, as it is a good indication of whether an employee is 'under the influence of drugs at work'. The dose of the drug taken has a significant effect on the clearance times. If you have a question about saliva drug test detection times, that is not answered here please contact our UK customer support team.

Saliva drug detection times & cut off levels for our drug tests

** Depends on parent compound still being deposited in the oral cavity.

Browse our saliva drug test kits, or workplace saliva drug tests for screening employees for recent use.

Cannabis (THC) Saliva Detection Times Explained

Cannabis (THC) saliva detection times are generally much shorter than urine detection windows because saliva tests are designed to detect recent drug use rather than past exposure. In most cases, THC can be detected in saliva for around 8–12 hours after smoking or vaping cannabis, although heavy or frequent users may test positive for longer. Factors such as frequency of use, oral hygiene, food and drink intake, and the sensitivity of the saliva drug test can all affect detection times. Saliva testing is widely used in workplaces and roadside testing because it provides a fast, non-invasive way to identify recent cannabis use.

Cannabis (THC) saliva testing is designed to detect recent use by identifying the presence of the parent compound THC, rather than long-lasting metabolites found in urine tests. This is why saliva tests are particularly effective at showing very recent consumption, often within 8–12 hours of smoking or vaping cannabis, although this window may be longer for frequent or heavy users. Because the test targets THC residue left in the mouth after use, factors such as eating, drinking, oral hygiene, and test sensitivity can all influence detection times. Saliva testing is widely used in workplace and roadside drug screening due to its speed, simplicity, and ability to detect very recent impairment-related use.

Fingerprint drug test detection times

The window of detection for drugs and their metabolites on a fingerprint drug test, is shorter than on a urine or saliva drug test for most drugs, at up to 16 hours.

More information on Fingerprint drug testing.

Hair drug test detection times

The detection window for drugs in hair can vary depending on several factors, including the type of drug, the individual's hair growth rate, the length of the hair sample, and the sensitivity of the testing method. Generally, drugs can be detected in hair for a longer period compared to other biological samples like urine, saliva or sweat. For most common drugs including Cannabis and Cocaine the detection period is around 90 days in hair.

It's important to note that hair drug tests are not necessarily indicative of current drug use but rather past use. The hair closest to the scalp represents the most recent drug use, so a longer hair sample will show a longer history of drug use. Additionally, hair tests are not always as sensitive as other types of drug tests, so they may not detect low-level or occasional drug use.

Which drug test should you use?

Whichever test you use, confirm any non-negative screening result with an accredited laboratory drug test.

FAQ drug test detection times

How long does weed stay in system after quitting?

The length of time cannabis (weed) stays in your system after quitting can vary depending on several factors, including frequency of use, method of consumption, metabolism, body fat percentage (THC is stored in body fat and then released slowly), and overall health. Here's a general guideline for how long THC (the psychoactive component of cannabis) can be detected in different parts of the body after quitting:

1. Urine: THC can typically be detected in a urine drug test for up to 30 days after last use for regular users. For infrequent users, it may be detectable in urine for just a couple of days. The new ultra sensitive lower detection level THC urine drug tests can now detect THC in the urine of some heavy frequent users of weed or Cannabis products for up to 60 days
2. Blood: THC is usually detectable in blood for up to a week after last use. However, it can be detected for a longer period in heavy users.
3. Saliva: THC can be detected in saliva for up to 72 hours using a laboratory test after use, but just a few hours is more usual for rapid saliva screening kits.
4. Hair: THC can be detected in hair follicles for several months after last use, depending on the length of the hair, although this method is less commonly used in drug testing due to its expense.

It's important to note that these are rough estimates and individual factors can cause significant variations. Additionally, as said before the newer and more sensitive urine drug testing kits may be able to detect very low levels of THC for longer periods of time.

How long does cocaine stay in urine and saliva?

Cocaine is usually detectable for 1–3 days in a urine drug test and 1–2 days in a saliva drug test. The exact window depends on the cut-off level of the test, how much was taken and how often it is used.

How long does amphetamine stay in urine and saliva?

Amphetamine is usually detectable in urine for 1–6 days on a 500ng/mL test, or 1–3 days on a 1000ng/mL test. In saliva it is usually detectable for 2–3 days.

How long does ketamine stay in urine and saliva?

Ketamine is usually detectable for 3–5 days in urine and 48–72 hours in saliva.

How long do benzodiazepines stay in urine?

Benzodiazepines are usually detectable in urine for up to 7 days, and for up to 6 weeks after heavy use of long-acting benzodiazepines. Saliva tests usually detect benzodiazepines for 2–3 days.

How long do opiates stay in urine and saliva?

Opiates such as morphine are usually detectable for 3–72 hours in urine and 7–21 hours in saliva.

How long does alcohol show up on a test?

An ETG urine test can detect alcohol for up to 80 hours after drinking, at a 500ng/mL cut-off. Saliva alcohol tests measure alcohol in real time, so they show whether someone has alcohol in their system now rather than earlier drinking.

Do ultra sensitive drug tests detect drugs for longer?

Ultra sensitive drug tests give a positive result at lower cut-off levels, but for most drugs they may not extend the detection period by a whole day. Cannabis is the exception: heavy long-term users have tested positive for up to 45 days on ultra sensitive 20ng or 25ng THC urine tests.

Related drug testing guides

• Cannabis saliva detection times
• Faint line on a drug test
• How to read drug test results
• False positive drug screen
• Urine drug testing FAQ
• Saliva drug testing FAQ

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