quest diagnostics drug test cutoff levels

Ĭommon known pharmaceutical drugs which cause false positives in instant THC dip tests include: However, a 2013 study conducted by researchers at the University of Utah School of Medicine refute the possibility of self-administered zinc producing false-negative urine drug tests. Similar claims have been made in web forums on that topic. In 2011, researchers at John Jay College of Criminal Justice reported that dietary zinc supplements can mask the presence of THC and other drugs in urine. Ĭannabis use is included in the '10-panel urine screen', as well as the 'SAMHSA-5', the five drugs tested for in standard NIDA approved drug tests.įalse positives have been known to be triggered by consuming hemp-seed bars, low THC cannabis and CBD supplements, although the more detailed, more expensive gas chromatography-mass spectrometer (GCMS) test can tell the difference. The antibody will then react with the drug-protein conjugate and a visible colored line will show up in the test line region of the specific drug strip. A drug, if present in the urine specimen below its cut-off concentration, will not saturate the binding sites of its specific antibody. During testing, a urine specimen migrates upward by capillary action. Drugs which may be present in the urine specimen compete against their respective drug conjugate for binding sites on their specific antibody. Urine testing is an immunoassay based test on the principle of competitive binding. Most cannabis drug tests yield a positive result when the concentration of THC-COOH in urine exceeds 50 ng/mL. The main metabolite excreted in the urine is 11-Nor-9-carboxy-THC, also known as THC-COOH. THC, the main psychoactive component of cannabis, may only be detectable in saliva and oral fluid for 2–24 hours in most cases. It also depends on whether tetrahydrocannabinol (THC) or its metabolites are being tested for, the latter having a much longer detection time than the former. However, every individual is different, and detection times can vary due to metabolism or other factors. In extraordinary circumstances of extended marijuana use, detection times of more than 30 days are possible in some individuals at the 20 ng/mL cutoff. Using a more sensitive cutoff of 20 ng/mL (less common but still used by some labs), the most likely maximum times are 7 days and 21 days, respectively. Under the typical 50 ng/mL cutoff used for cannabis testing in the United States, an occasional or on-off user would be very unlikely to test positive beyond 3–4 days since the last use, and a chronic user would be unlikely to test positive much beyond 7 days. Marijuana use can be detected up to 3–5 days after exposure for infrequent users, 1–15 days for heavy users, and 1–30 days for chronic users and/or users with high body fat. The length of time may vary to some degree according to metabolism, quantity, and frequency of use.

Metabolites of cannabis are usually detectable in urine drug tests from 3 days up to 10 days according to Redwood Laboratories heavy users can produce positive tests for 30 days or longer after ceasing cannabis use. Most cannabinoids are lipophilic (fat soluble) compounds that easily store in fat, thus yielding a long elimination half-life relative to other recreational drugs. The Duquenois-Levine test is commonly used as a screening test in the field, but it cannot definitively confirm the presence of cannabis, as a large range of substances have been shown to give false positives. The concentrations obtained from such analyses can often be helpful in distinguishing active use from passive exposure, elapsed time since use, and extent or duration of use. The lack of suitable tests and agreed-upon intoxication levels is an issue in the legality of cannabis, especially regarding intoxicated driving.

Unlike alcohol, for which impairment can be reasonably measured using a breathalyser (and confirmed with a blood alcohol content measurement), valid detection for cannabis is time-consuming, and tests cannot determine an approximate degree of impairment. Cannabis use is highly detectable and can be detected by urinalysis, hair analysis, as well as saliva tests for days or weeks. Cannabis drug testing describes various drug test methodologies for the use of cannabis in medicine, sport, and law.

Quest diagnostics drug test cutoff levels