Window of Detection & Adulteration Level
When choosing a test that's right for you, consider these 4 factors:
- The substances that need to be detected (Drug Panel Selection)
- Desired window of detection
- Specimen Type
- Level of adulteration potential
Urine Drug Test
A urine test is one of the most established drug testing methods that have a detection window of up to 30 days. In this test, your urine sample is checked for metabolites, which are a by product of when your body breaks down a drug substance.
A urine test also analyzes antigen-antibody complexes, which form when your immune system releases antibodies in the event a drug substance enters your system.
Although urine is the most commonly used specimen for point-of-care testing, there have been concerns about the slight likelihood that urine samples may be tampered with or substituted. To reduce this risk, an observer may directly watch the sample being collected.
Adulteration Level: Easy
Blood Drug Test
A blood test is usually performed during emergencies but can also be used to detect drug compounds for pre-employment tests. Blood tests are usually an integral part of annual physicals.
Compared to other testing methods, collecting the specimen is more invasive, since it requires drawing a small amount of blood from the vein. It is also limited to recent substance use, within 2 to 12 hours prior to the test.
Adulteration level: Difficult
Hair & Fingernails Drug Test
A hair or follicle test needs a strand of your hair from your face, head, or armpit. It’s useful in providing information on a person’s cumulative substance use.
Of all testing methods, a hair & fingernails test offers the longest window of detection.
Hair from your scalp has a detection window of three months, while body hair has a window of up to 12 months. This long detection window is attributable to the tendency of drug metabolites to remain in the hair from one week after drug use up until the hair grows. As such, a hair test can offer a timeline into how long a person has been using an illicit substance.
Fingernails offer a window of detection of up to 6 months, while toenails has a window of up to 12 months. Fingernails are made up of keratin, the same material that hair is made of. As the nail grows, substances can pass from the blood vessels below the nail into the keratin fibers, where they become trapped. Fingernails are four times thicker than the typical strand of hair and often capture more of a substance than hair can. Biomarkers become locked in keratin fibers along the entire length of the nail and can be detected up to 3-6 months after drug or alcohol abuse.
However, it is not without limitations. A hair test may not be highly capable of detecting low-level or single-use cases.
Adulteration Level: Moderate
Oral Fluid Drug Test
During an oral fluid test, your mouth is swabbed to collect saliva, which is then analyzed to detect the concentration of orally consumed substances. In some cases, it can catch same-day use or residual drugs in the mouth.
However, a saliva test is not without disadvantages. Saliva production may be limited due to drug use. It also has a short window of detection of approximately 24 to 48 hours after last use.
Adulteration Level: Difficult
Sweat Drug Test
During this test, you may be required to have either an absorbent pad placed on your skin for less than 24 hours or wear a sweat patch for seven to 14 days. Like a hair test, a sweat test gives an insight into a person’s cumulative substance use. Compared to urine samples, sweat specimens are difficult to tamper with and possibly more affordable.
Adulteration Level: Difficult