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Urine Drug Testing

Introduction to Urine Drug Testing

Urine testing is the most extensively studied and used type of drug testing.[1] Urine testing is conducted for law enforcement, pain management compliance, employment vetting and compliance and abstinence program compliance.

Advantages of urine drug testing

  • Large sample allows for ease of retest and confirmatory test.
  • Non-invasive acquisition of samples.
  • Inexpensive for screening tests.
  • High concentrations of substances and metabolites.
  • Extensively researched and scientifically validated.
  • Screening tests are available for point-of-care testing.

Disadvantages of urine drug testing

  • Susceptible to dilution.
  • Susceptible to adulteration.
  • Susceptible to substitution.
  • Short to intermediate window of detection.

Availability of at home urine drug screening products

There are many commercially produced urine drug screening products available for public purchase. Not all of these will have undergone the same extent of reliability and validity testing as those used by governmental agencies. You can find an overview of many commonly available self-screening products and reviews by other site members here.

Methods used to subvert urine drug testing


Dilution involves the person being tested consuming excessive fluids and/or diuretics prior to providing a sample. This has the effect of lowering the concentration of metabolites in the urine. More advanced testing methods employ validity testing to check for dilution. Creatinine is a natural substance found in urine, and dilution can be identified by lower levels of creatinine in the sample. Some point-of-care tests now test for creatinine levels. Specific gravity is a measure of the number of particles in the urine, with low levels indicating dilution. Specific gravity testing is used to confirm dilution on samples with creatinine levels below the cutoff of 20mg/dL.[1]


Adulteration is the introduction of foreign substances to the sample. Some substances may mask the presence of parent drugs or metabolites in the sample. Validity testing for adulteration may include testing for specific commonly used adulterants and/or the pH level of the acidity of the sample.[1]

Substitution and commercial synthetic urine products

Substitution is the replacing of the intended sample with a different sample. A method often employed is for the person being tested to request a sample from an abstinent friend and substitute the sample at the time of testing. Methods of preventing substitution generally involve close observation of the provision of the sample so as not to provide an opportunity for the sample to be exchanged.[1]

Commercial synthetic urine products are produced and available for purchase for the purpose of substituting in urine drug testing. An overview of what products are commonly available and reviews of these products by other site members may be found here.

Commercial detox products

Many commercial products are available for public purchase which claim to assist with detoxification. It is not clear how effective these are and you should review the scientific literature on these products, some of which can be found in the studies archive here. An overview of commonly available detox products and reviews of them by site members can be found here.

Approximate detection window for common drugs using urine drug testing

Unless otherwise noted the detection times listed here are for a single occasion use of a substance. Generally the detection cutoff thresholds are sensitive enough to detect any recreational dose for a non-tolerant user of these substances. Chronic administration usually leads to a build up of substances and their metabolites and consequently longer detection windows. Tolerance is not a significant factor in the elimination of the substance and its metabolites. Tolerance mostly reduces the pharmacodynamic response to a substance, rather than affecting the pharmacokinetic activity on the substance. This means that tolerant, chronic users of drugs are more likely to test positive regardless of whether they actually got high from the substance. Physiological differences such as kidney or liver impairment and the general metabolic rate can vary between individuals which can affect the detection window.
Substance Detection window
Alcohol 6-24 hrs (5 days with EtG)
Amphetamines 1-4 days
Barbiturates 1-21 days
Benzodiazepines 1-42 days
Cannabis (single use) 2-3 days
Cannabis (habitual use) 15-30 days
Cocaine 4-5 days
Codeine/Morphine 2-4 days
Heroin (6-MAM) 2-4 days
Methamphetamine 3-5 days
PCP 3-7 days
GHB and prodrugs 12-24 hours
JWH-018 and JWH-073 up to 72 hours

Comparitive detection windows for different types of sample can be found here


  1. ^ a b c dCenter for Substance Abuse Treatment (U.S.) United States. Substance Abuse and Mental Health Services Administration. RTI International. Knowledge Application Program (U.S.). (2012). Clinical drug testing in primary care. Rockville, MD: U.S. Dept. of Health and Human Services, Substance Abuse and Mental Health Services Administration, Center for Substance Abuse Treatment.
Categories: Drug Testing

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