Hair Testing and Urine Testing

Urine has always been an effective method of drug testing. However the test typically only reaches as far back as 9 to 10 days. On the other hand, Hair Testing can detect past months of usage.

The results below are based on companies of varying sizes and show the difference in the testing of urine and hair. American Toxicology believes that the best fingerprint of drug use is obtained by testing both hair and urine. The following illustrates the comparisons between hair and urine testing of four of our clients.

Company 1: # of total tests: 10,558

Drug……………….Pos/Urine…………..Pos/Hair
Amphetamines…………29…………………….158
Cocaine………………...256…………………...730
Heroin………………….0………………………...0
PCP…………………….1………………………...2

Company 2: # of total tests: 3,953

Drug……………….Pos/Urine…………..Pos/Hair
Amphetamines…………12………………………50
Cocaine………………...11…………………........28
Heroin………………….1…………………….…...1
PCP…………………….0………………………....0

Company 3: # of total tests: 209

Drug……………….Pos/Urine…………..Pos/Hair
Amphetamines…………0………………………....3
Cocaine………………...1…………………............7
Heroin………………….0…………………….…...1
PCP…………………….0………………………....0

Company 4: # of total tests: 52

Drug……………….Pos/Urine…………..Pos/Hair
Amphetamines…………0…………………………1
Cocaine………………...1…………………............3
Heroin………………….0………………………....0
PCP…………………….0………………………....0

Results indicate that hair and urine testing is far superior tot urine testing alone in identifying drug users attempting to become employed. Over 2/3 of the applicants testing positive by hair would have passed the urine test and became part of the employee population. Marijuana is not shown in this example because it is best detected in the urine.

Because it takes approximately a week for ingested drugs to show up in hair above the scalp, American Toxicology strongly suggests using both urine & hair testing for a complete history of drug usage to help maintain a drug-free work environment. Studies continue to show that marijuana (THC) is best detected in urine. THC is a fat soluble drug that stays in the body much longer than any of the hard drugs. As a result, the body will shed THC for weeks or even months. Once again, for optimal results American Toxicology strongly recommends a Hair & Urine test for all clients.

Urine Drug Testing

This procedure requires that one provide a sample of urine. Either a test card is used on site for immediate results (see "General" section), or the sample is sent away to a lab to undergo gas chromatography/mass spectrometry (also known as GCMS), high performance liquid chromatography or immunoassay analysis. The majority of tests administered in pre-hire and even most probate scenarios are of the immediate, and less accurate "at home" variety. Most "dip stick" type tests have higher thresholds for a positive than do the GCMS tests. If a positive result (drug presence indicated) is found, the sample is usually sent to a lab for GCMS confirmation. This is largely due to the costliness of GCMS labaratory testing and time it takes to process and receive results. The results of any urine test reflect factors including, but not limited to age, weight, race, and often these factors are what determines whether the test is valid or not.

The efficacy of urine testing is debatable due to systematic cheating. It is widely reported that sample substitution and adulteration occur frequently, and both are effective methods of avoiding would-be positive tests. There are a number of adulterant "masking" agents that are sold, though they are often nothing more than a simple diuretic and are rarely more effective than caffeine. Some people drink copious amounts of water to successfully dilute the concentration of drug metabolites in their urine below detectable thresholds. Often this results in clear samples that may be rejected on the grounds of being too dilute, although a complex B vitamin will make urine yellow despite this practice of waterloading. Specific gravity testing can be done to identify whether or not the sample is of dilute nature, though this is used infrequently on otherwise inconspicuous samples. The substance Niacin is also frequently used for its reported "flushing" effect, though this is also of disputable adeptness. Some types of urinalysis can detect the use of these "detox" products, though they are rarely used unless some facet of the sample is suspicious. Also, the wide availability of at home drug screens allows an individual to take their own test before they receive one, thus knowing the results ahead of time- giving the user further opportunity to dilute the sample or to find a substitute.

This helpful information was provided to us by Wikipedia.

American Toxicology is a full service drug testing laboratory in Las Vegas, Nevada. We are proud of our excellent service and our quality results. With our new online reporting we are able to provide results same day (for locals) within 2-6 hours!