The Los Angeles Medical Marijuana Blog

The effects of smoking marijuana fade quickly, but the drug can be detected in the body for weeks and sometimes longer. How long it remains in the system depends on how often or how much marijuana the user has been smoking.
The Los Angeles Medical Marijuana reminds people who have been using marijuana that the active ingredient in marijuana — Tetrahydrocannabinol or delta-9-THC or simply THC — enters the body’s bloodstream rapidly after smoking marijuana. If marijuana is ingested, rather than smoked, it takes longer to be absorbed into the blood, usually from 20 minutes to an hour and a half.
Some THC metabolites have an elimination half-life of 20 hours. However, some are stored in body fat and have a elimination half-life of 10 to 13 days. Researchers from Los Angeles Medical Marijuana agree that urine tests for marijuana can detect the presence of the drug in the body for up to 13 days.
However, there is anecdotal evidence that the length of time that marijuana remains in the body is affected by how often the person smokes, how much he smokes and how long he has been smoking. Regular smokers have reported positive drug test results after 45 days since last use and heavy smokers have reported positive tests 90 days after quitting this is based on the study conducted by Los Angeles Medical Marijuana Id.
Although false positives are common for other substances, they are rare for marijuana due to the sophistication of today’s tests. The laboratory first screens the sample with a immunoassay test, known as the EMIT or RIA. If positive results are returned, the sample is again screened with a gas chromatograph mass spectrometer (GCMS), which is much more accurate. That’s why false positives are rare.
According to Los Angeles Medical Marijuana no known substances would cause a marijuana urine test to return a false positive. At one time, ibuprofen — sold over-the-counter as Advil, Motrin, Nuprin and others — would cause false marijuana positives. But today’s tests have been adjusted to eliminate that problem.
On the other hand, urine tests done at the Los Angeles Medical Marijuana clinics for marijuana metabolites can only show recent marijuana use, not intoxication or impairment, because of the time required between smoking and the metabolites being eliminated in the urine. However, because many employers have a zero tolerance for drug use, most workplaces use urine tests for any recent use of drugs.
If you are required to take a urine test on short notice for employment or other purposes and you have recently smoked marijuana, you are probably going to fail the test. This is particularly true if you are a regular or heavy pot smoker.