The Essentials Of Medical Marijuana Drug Testing
Urinalysis is the most common method of drug testing in the US for marijuana, narcotics, and illicit substances. Marijuana can stick around in a person's system for weeks in sufficient amounts to produce a positive urinalysis.
The interesting thing here is that a positive drug test may mean the individual isn't currently intoxicated with arizona medical marijuana, and hasn't been under it for days. What is being tested with a marijuana drug test? It is not actually THC, also known as tetra-hydro-cannabinol, which is a psychoactive element of medical marijuana arizona.
What's being evaluated is one of the non-psychoactive cannabinoid metabolites called THC-COOH. This metabolite is produced by the liver, and is indicative of substantial metabolic degradation having already occurred. There is no correlation between a positive test and a current state of marijuana intoxication.
Unfortunately, this means urine tests are incapable of distinguishing between weekend use, regular use, or on-the-job impairment.
Blood testing for marijuana is the most accurate test available, as it tests the actual presence of THC in the bloodstream. It actually tests the current presence of the psychoactive component in the blood. After utilizing medicinal marijuana, a blood test will register positive for a few hours. In the first 10 minutes of smoking marijuana, THC levels peak sharply and then drop off dramatically over the next few hours.
Blood tests can also detect for the metabolites of THC similar to the urine testing. It can test for two metabolites, one inactive and one active. The inactive metabolite is THC-COOH and is the same as the urine. The active one is called 11-OH-THC and is psychoactive. Blood levels mirror those of THC itself, rising two to six hours steadily after smoking.
Although it hasn't been clearly shown in the literature, people think they can definitively show when a person last used marijuana by evaluating the ratios of these 3 substances.
Hair testing for marijuana does not measure current use, but that from days, weeks, or months past. Hair strand testing evaluates metabolites that have settled in the base of the hair follicle. Shampoos that state they will allow for a negative drug test may in fact clean the residue off the hair strands, but eliminating the residue from the hair follicle will be impossible as the metabolites end up in the structure of the hair.
Saliva drug testing offers the benefit of being less messy and less smelly. It is commonly used in regular drug testing to check for narcotics, and in most narcotics the results with laboratory testing are the same. But this is not the case with medical marijuana in arizona, and the results have not achieved reliability.