Methods of Marijuana Drug Testing

Marijuana drug testing is performed to detect the presence of THC or its metabolites in the consumed person. Marijuana in an individual can be detected for a month or longer. The time that marijuana stays in the body varies based on certain factors including age, health, metabolism, and concentration of marijuana consumed. Marijuana drug testing can be done in different types that include urine test, blood test, saliva test, sweat test and hair test.

Urine Test:
The urine test is performed to detect 11-nor-delta-9-tetrahydrocannabinol-9 carboxylic acid (9-carboxy-THC) which is a metabolite of THC. Certain cut-off values for the drug are given by the regulatory organizations. The accepted cut-off value in urine for THC metabolites is 50ng/ml. If the concentration of the metabolites is greater than 50ng/ml then the test is resulted positive. The urine drug test that is conducted to detect marijuana is termed as urinalysis.

Blood Test:
Blood test is the most common type used for detecting the drug. The concentration of the drug in blood can be known even it is consumed an hour before the test is performed. This method gives an accurate measurement of the drug. The blood tests for marijuana are performed in cases such as autopsy, road traffic accidents, and intoxication.

Saliva Test:
Saliva test is an easiest way of marijuana drug tests but is more expensive when compared to urine and blood tests. This method gives accurate and quick results. The advantage of saliva test is that it can detect the drug that is consumed most recently. Also more amount of the drug, instead of its metabolites, is detected through saliva tests. .

Hair Test:
Hair test can be conducted to detect THC. The compound gets deposited in the hair shafts after passing through the blood vessels in the scalp. So even a small part of the hair shaft can be used for marijuana drug testing. Using this method the drug can be detected even after 90 days of the drug consumption.

Sweat Test:
Sweat test is performed by applying a patch on the skin for 10 to 14 days. Later it is sent to the laboratory for testing. The patch can detect marijuana that is consumed even before hours of performing the test.

Factors Which can Alter The Result Of Marijuana Drug Test

As the use of drugs is increasing day by day, drug testing is also increasing along with the drug usage. While taking the case of marijuana, mostly urine test is performed for detection. The test can be done in any place whether it may be in schools, colleges, work places etc.

But, there are some factors which alter the results or getting false positives. Some of the factors are human errors, medications etc.

Human Errors:
In general, after screening test is done, a confirmatory test is done. For the confirmatory test the urine sample is sent to the laboratory, for conducting Enzyme multiplied immunoassay technique. During the conduction of the test, human errors will occur. These human errors are caused because of labeling or because of lack of proper training for the staff, because of negligence. All these make the result to be positive which is not true.

Medications:
Some of the medications will also give false positives for the tests which are done. So, many medication companies are warning regarding the false positives of the test. So, the tested person should be careful while the marijuana drug test is done. He/She should bring the prescription as well as the medications while the test is done. Some of the medications like non-steroidal anti-inflammatory medications, medications which are used for controlling nausea and vomiting may also cause false positives when marijuana drug test is conducted.

Other factors:
Some of the Kidney disease medications, liver disease medications, Hemp seed oil, diabetes medications will also give false positives for the marijuana test. So, it is better to carry a bottle or pill of medications to show.

These are the different factors which lead to false positives of marijuana drug test.