The question “How long does marijuana stay in your system?” is a popular one online. It is more difficult than you think, but it is crucial if you administer a drug test.
First, you need to know that marijuana is still present in the body, even though someone isn’t experiencing any effects or “high” from it. And it is not so much marijuana that is in your system, but its active chemical, THC (Tetrahydrocannabinol).
Drug tests for THC are performed by analysing saliva, urine, blood, or hair. Surprised at the variation in THC levels in consumer drug tests based on saliva, hair or urine?
The saliva test detects marijuana quickly, so it takes longer to detect than other drugs. A home saliva drug test can detect marijuana within one hour of its use. It takes approximately 12 hours for marijuana saliva to start leaving the mouth. After that, home saliva drug tests mail order marijuana are less accurate.
The amount of marijuana used and the frequency with which it was smoked can make a big difference in the time that THC can be detected in urine. The THC can remain in your urine for as long as 45 days. It is most common to have it stay in your urine for between one and three weeks. A person who has been using marijuana regularly or daily for at least three weeks can expect to test positive after quitting. One-time users shouldn’t expect to receive a negative result on a drug test because they have only used the drug once. A urine drug test can still detect positive results from just a few days to more than a week after their last use. Generally, marijuana use can be detected in urine within 2-5 hours of initial use.
Even though marijuana/THC may not have been in your saliva or urine, it can still remain in your system through your hair follicles. The bloodstream is affected by drugs you have consumed. The blood feeds hair and allows it to grow. Drug traces can get trapped in blood and cause hair loss. The hair will begin to grow away from the scalp after about one week of drug abuse. Drug use can then be detected in the hair. Drugs can take a long time to cause hair loss. Consumer hair testing labs only have a 90-day limit, but courts and other authorities may require a test that examines hair for a longer time. Your body hair may also contain drug traces. Because body hair grows slower, the detection window is one year. One caveat to hair drug testing is that marijuana doesn’t always mix well with hair. This means that even someone who smokes a lot may be negative. This is not a common phenomenon with cocaine or other drugs that are commonly tested for hair. Hair drug testing is able to detect marijuana in your system but is less reliable that urine tests which are 98% precise.
The frequency with which you use marijuana can have a significant impact on how long it stays in your system.
THC is fat-soluble and is absorbed by fat cells when marijuana is smoked. After a few days, the THC will begin to diffuse into the bloodstream and your body becomes clean. If you continue to smoke, the THC in your blood will diffuse more quickly into your body, making it easier for THC (and thus evidence of marijuana use) to remain in your system. The New Scientist is a scientific journal that documents rare cases in which former heavy users, who have experienced significant weight loss, begin to release “old” stored THC into their bloodstream.
When you ask how long marijuana remains in your system, be sure to clarify: What part of the system? These are important questions to ask if you’re testing a child or employee suspected of using marijuana long-term. Because marijuana’s effects are so varied, it might be a good idea to purchase a drug test to determine if the person or child you wish to test is clean.