Last updated: June 5, 2023
Metabolism is a constantly occurring process within every cell of your body. It’s necessary to maintain life. The body metabolizes everything put in it whether it’s life-sustaining or not. For instance, your body metabolizes the THC in marijuana. Marijuana metabolites stow away in your body anywhere from a few days to over a month. How come weed stays in your system so long?
The growing popularity of marijuana use in the country is on the rise due to legalization, which started in Denver, Colorado, and quickly spread across America. This led to a renewed interest in testing procedures and how long and effectively they can detect the drug in someone’s system.
Legalization poses a challenge for employers, with some choosing to begin testing for marijuana use, and others choosing to stop. Advocates for legalization, of course, call for entirely removing it from company drug testing.
Pot has been one of the most commonly tested substances for years. It’s included on the majority of—if not all—standard drug testing panels. There are multiple ways to detect its presence in the system. While many people are aware of the various technologies, they’re often unsure about how long each test detects marijuana.
Standard drug panels, which include 5 panel, 10 panel, 12 panel and DOT drug tests, commonly include marijuana. In other words—unless specifically removed, any of these tests could be considered a marijuana drug test.
To understand how long marijuana stays in the system, it’s important to know what happens when the drug is used. THC is released when inhaling or consuming pot. It metabolizes rapidly in the body, creating euphoric effects. While these effects are short-lived, the byproduct, a metabolite named tetrahydrocannabinol carboxylic acid (THC-COOH) stores itself throughout the body awaiting excretion.
Drug tests commonly detect the metabolites that drugs leave behind. Detection periods vary, however, depending on the testing method. Marijuana metabolites mainly store themselves in the fat cells and are detected in the urine test long after impairment.
To truly answer the question of how long marijuana stays in the system, though, depends on several factors.
- Amount consumed
- Method of consumption
- Frequency of use
- The testing method used for identification
Marijuana in the blood
Marijuana is detected for the shortest time using a blood test. To test positive on a blood test, THC has to enter the bloodstream either through inhalation into the lungs or absorption through the lining of the stomach. If you smoke weed, THC enters your bloodstream within seconds of inhaling it. Edibles take a bit longer as they go through the digestion process before entering the bloodstream.
THC travels through the bloodstream up to the brain producing the effects of being high. After consumption, the body immediately begins metabolizing the active THC in the blood, breaking it down.
Blood tests aren’t used very often when testing for marijuana though. This is mainly due to the intrusive nature of the test and they are very expensive. Moreover, the detection period is extremely short-lived. Typically, THC remains in the bloodstream for just three to four hours.
Employers and workers’ comp insurance companies do use them in post-accident situations though. Blood tests detect the parent drug and, therefore, detect current impairment. This information can be very useful in determining the accident’s cause.
Marijuana in saliva
The saliva test detects marijuana use almost immediately, but it only yields a positive result for approximately 24 hours after consuming it. However, the body is constantly producing saliva so claims of ways to cheat the test are false. Also, the test subject never leaves the administrator’s sight so tampering isn’t a possibility either.
Delta-9 THC, a psychotropic substance, coats the inside of the mouth and absorbs into the salivary glands after smoking. It happens when you chew edibles as well. The THC hangs around until new saliva washes it away.
Recent advances in technology coupled with a detection window of up to 72 hours (depending on the drug) make the mouth swab test a solid choice for those who want to determine recent drug use. It’s for that reason employers and law enforcement agencies use this test more than ever before.
Marijuana in urine
The most frequently used employee drug test is the urine test. Employers choose them for many reasons. They are cost-efficient, extremely accurate, and expected. When an employee hears the words “drug test,” they usually assume a urine test is coming up.
Since the by-products of using marijuana are fat-soluble, they bond to the fatty tissue in the body which causes them to take longer to expel. Also, cannabinoid metabolites vacate the body at different rates depending on certain body traits, such as body mass index, for instance.
Someone who rarely uses marijuana in any form is likely to pass a urine drug test after three days. This is because the amount of THC-COOH stored throughout the body has either dissipated or isn’t exiting the body at levels high enough to register.
A moderate user, someone who ingests THC up to four times a week, will test positive for up to five days. It makes sense that if the body stores THC-COOH, the more often one uses it, the greater the number of metabolites stored away in the body. Therefore, tests detect them for a longer period of time.
Par for the course, a daily marijuana user will test positive for up to ten days after discontinuing use. The cleansing process is constant so refraining from marijuana use allows your body to excrete the THC metabolites after this period of time.
Lastly, someone who is a chronic marijuana user is likely to test positive for thirty days or longer. This also stands to reason because the body is constantly retaining THC-COOH. Again, the more often one uses, the greater the number of metabolites stored.
There is a concern of tampering with or substituting specimens due to the privacy required during the test. However, thanks to advancing technology in the industry coupled with the very sophisticated laboratory equipment used today, it’s harder and harder for cheaters to succeed.
Marijuana in hair
The hair follicle drug test creates a permanent record of drug use. This is because the drug metabolites that store themselves in the hair follicle grow out and become part of the hair itself. These tests are extremely accurate and there is virtually no way to falsify the results.
Employers use the hair follicle tests the least. The cost factor is likely a big contributor to that fact. These days, though, many employers are taking a second look because the test determines if there was any marijuana use over a period of ninety days. Human hair grows at a rate of about 1/2 per month. Therefore, a hair sample measuring one and one-half inches equals a ninety-day detection period.
Notably, if someone has used the drug for the first time within a week of testing, it’s possible that they will obtain a negative test result. It takes a few days for the metabolites to show up because they need time to grow out of the hair follicle and into the hair shaft.
However, once it’s there, it’s there for good.
Why do detection times vary?
We hit on the fact that the more you use, the greater the number of THC-COOH metabolites that are stored throughout your body. Moreover, there are other contributing factors to consider regarding detection times.
Growers continue to try and increase the THC levels contained in marketed marijuana. Plants containing higher levels of THC mean retaining higher levels of THC.
Specifics play a part
An individual’s metabolism is another determining factor. For whatever reason, one person tests positive longer than another. It has to do with the way each body metabolizes the drug. Basically, it boils down to DNA.
Being in shape makes a difference. THC-COOH mainly collects in the fat cells. Thin people don’t have as many fat cells. If you are overweight, the likelihood increases that there is a virtual warehouse full of the stuff!
Cannabis has psychoactive and physiological effects when consumed. Aside from a subjective change in perception and, most notably, mood, the most common short-term physical and neurological effect is food consumption—you know—”the munchies.”
Other symptoms include:
- Increased heart rate
- Increased appetite
- Lowered blood pressure
- Impairment of short-term and working memory
- Impaired psychomotor coordination
- Inability to concentrate
Long-term effects are less clear.
While many psychoactive drugs clearly fall into the category of stimulant, depressant or hallucinogen, cannabis exhibits a mix of all properties, perhaps leaning the most towards hallucinogenic or psychedelic properties, though with other effects quite pronounced as well.
Methods of consumption
Users consume marijuana (cannabis) in many different ways, most of which involve inhaling the smoke.
- Small pipes
- Bongs (a portable version of a hookah with a water chamber)
- Paper-wrapped joints
- Tobacco-leaf-wrapped blunts
- Vaping devices
Alternatively, the cannabis plant flowers may be finely sifted producing kief, a powder especially rich in the oil-glands or trichomes which contain the highest amounts of cannabinoids.
When someone smokes marijuana, impairment occurs almost immediately. The THC passes from the lungs directly into the bloodstream. Once in the blood, it races to the brain and other organs throughout the body. The “high” peaks in about an hour, and lasts for several hours.
Edibles, on the other hand, often take several hours to reach the height of impairment. The user begins to feel the effects of the drug about 30 minutes after consumption. They are “back to normal” after about five hours.
They say it’s not addicting
Cannabis can be habit-forming and the development of cannabis dependence in some users has been well established. Its effects on intelligence, memory, respiratory functions and the possible relationship of cannabis use to mental disorders such as schizophrenia, psychosis, Depersonalization disorder and depression are still under discussion.
The sense of euphoria that accompanies smoking pot is due to the release of dopamine in the brain. During the hours of impairment, users experience any or all of the following.
- an altered sense of time
- changes in mood (often described as mellow)
- impaired body movement
- difficulty with problem-solving and focus
- impaired memory
In the case of a very high dose of THC, hallucinations, delusions or even psychosis can occur.
Also alarming, some studies show that chronic users exhibit motor skill impairment for days or weeks after discontinuing use.
Studies have shown that people who smoked marijuana heavily in their teens and continued heavy use into adulthood lost an average of 8 IQ points before they were forty. However, those who began smoking as an adult did not show a decline in IQ.
There are studies that show that people who smoked the drug heavily in their teens suffer from impaired thinking, learning, and memory skills. It appears that the drug affects how the brain builds the connections necessary to complete these tasks.
It’s unclear, however, if this is caused by the THC itself or predisposition factors in the DNA.
It’s CBD not THC
It comes as a surprise to some CBD users that taking CBD products puts them at risk of testing positive for marijuana use.
Especially, if someone used the product just before a drug test, oh by the way. They may test positive for the test but take a test later in the day with a negative result. By the way, we conducted an in-house test of our own that produced this result. Moreover, the CBD product our volunteer took advertised that it was THC free!
There are testing measures in place to regulate the extraction process. Therefore, it is impossible to ensure that THC levels fall under a specific range. If products promoting zero amounts of THC contain enough to produce a positive test result, it stands to reason that any CBD product warrants a risk of a positive test result.
It might be a good idea to educate your employees in regard to this information. They may rethink the decision to use CBD for medicinal purposes.
Reasons to conduct a marijuana drug test
A documented drug testing policy is designed both to protect the company from liability and to educate employees on what’s expected. This drug policy should be fair and reasonable, clearly stated, fully explained, and compliant with all applicable laws at the local, state, and federal level, in the locations where the company has employees.
Failing to do this may result in invalidated test results and possibly even an HR-related lawsuit. Fortunately, following a written drug testing policy eliminates these situations. It may include any or all of the following drug testing requirements.
Pre-employment drug test
As one of the most common reasons to perform a drug test, a pre-employment drug test is intended to weed out potential employees who use marijuana or other drugs. This helps employers avoid problem employees in the first place.
Random drug test
A random drug test ensures that employees did not merely refrain from drug use during the applicant phase. It also helps to maintain higher workplace productivity, morale, and safety because employees know they are subject to a drug test at a moment’s notice. The Department of Transportation requires random drug tests, but some employers of the general workforce do so as well.
Post-accident drug test
Immediately after an accident, an employer may conduct (or may be required to conduct) a post-accident drug test. In addition to regulatory and/or workers comp insurance reasons, this also discourages drug use since employees know they can be tested if they are involved in a workplace accident.
Reasonable suspicion drug test
A reasonable suspicion drug test may be conducted if a supervisor suspects drug use based on appearance, behavior, speech, smell, and other indicators. Your drug testing policy must clearly document what indicates reasonable suspicion.
Return to duty
After a positive drug test result, the DOT requires a return to duty drug test before an employee returns to a safety-sensitive role. This is intended to ensure the employee has not consumed any drugs since the last drug test.
DOT drug test
Employers bound by the Department of Transportation regulations must conduct a DOT drug test in specific situations. As opposed to non-DOT employers, this is not optional and must be conducted according to DOT regulations.
Weeding through it all
In a tightening labor market, some employers believe the incentive to test less looks enticing as marijuana drug testing does have a cost, and, if it’s legal, why bother? This thinking, however, ignores the safety and productivity impact of marijuana use. For companies operating in multiple states, inconsistency regarding law-making creates problems with standardization of compliance policies company-wide.
Furthermore, marijuana use is still illegal at the national level. However, in November 2019, the House passed the Marijuana Opportunity Reinvestment and Expungement (MORE) Act. If it passes the Senate the federal government will remove marijuana from the controlled substance list.
Our society has deemed pot to be a harmless drug. As a result, its use is becoming more and more widely accepted. Still, employers have every right to remain concerned.
The reason we drug test
No matter how they consume it, employees under the influence of marijuana—or any drug—usually become less productive. More importantly, it’s a proven fact that marijuana use affects motor and cognitive skills, possibly for an extended length of time. There is no doubt that marijuana users increase the risk of workplace accidents.
In the long run, it is much more cost-effective to maintain a drug-free workplace. In order to avoid the effects of marijuana use, it’s critical to have a clearly defined workplace drug testing policy. It should contain procedures for employee and supervisor education, testing protocols, repercussions for drug use.
Drug testing in the workplace deters some from choosing a lifestyle that includes smoking weed. Routine reminders of your company drug policy or on-site refresher courses regarding the dangers of drug use act as further deterrents.
Much like the process of metabolism that goes on within every cell of our bodies, promoting a drug-free workplace is an ongoing process. In the same fashion, just as metabolism is necessary for sustaining life, educating your employees about the dangers of taking drugs could sustain a life too.
Keep up the good work.