There is only one reason for someone to care how long cannabis remains in their body (unless you are a researcher or writing articles like this one). People wonder how long marijuana will last in their system because they are worried about having to be tested for drugs. And, as you will surely know, employers can use a different type of test.

The short answer is 1 to 30 days after the last use. But as with other drugs, it may be detectable in hair for several months. Cannabis detection windows depend on how much you smoke or ingest, as well as how often. In general, higher doses and more frequent use are associated with longer detection times. For daily users, cannabis may be detectable for several months after the last use. Longest-reported detection times are more than 90 days.

So the question really needs to be explained differently: How long can weed be found in blood, urine, saliva, and hair?

The answer is still not easy given the many variables to consider. How much does a person smoke or consume and how strong are weeds? How often do you smoke and your weight?

And are you really concerned about how long marijuana lasts in the body – or how long it takes to detect signs of marijuana?

That’s a lot of questions. Let’s dig deeper and find some answers.

How Long Does Cannabis Stay In Your System?
Tracking THC in your blood stream

Track the THC in your system

The best way to know how long marijuana will last in your system and how it will be detected is to know exactly how the process works.When you smoke (or scrape) the pot, activated THC and other cannabinoids hit your lungs and then enter your bloodstream, where your heart pumps them around your body. THC then binds to cannabinoid receptors (and receptor proteins) in major systems and organs of the body, including the brain. This is how marijuana’s psychoactive effects can work.

The process is similar but faster with tinctures quickly absorbed through the lining of the mouth. These are similar, but slower, to edible ones, in that they are first absorbed by the digestive system before reaching the liver and then the bloodstream.

Something else happens to THC because it’s carried in the blood. It passes through the liver several times and each time a large part is converted into a number of other substances. The most important ones (for our purposes) are called THC-COOH and 11-OH-THC and do not have any important functions. However, these metabolites are stored in body fat and stay there longer than THC itself. It is important to them.

Once you have that information, here’s the question. If you wanted to find out if someone had used marijuana in the past month, would you test for THC, which is normally found in the body in just 1-10 days, or test for THC metabolites stored in body fat for a month or more?

The answer is obvious, so most of the tests used by companies are looking for THC-COOH or 11-OH-THC. This metabolite is more of a long-term indicator of whether a person has used the potty.

Blood, saliva, urine and hair, urine and hair

If the title of this section doesn’t make sense to you, try singing it in a “head, shoulders, knees and feet, knees and toes” tone. (And no, we’re not wasted now, it looks fun.)

As mentioned earlier, people don’t want to know how long marijuana lasts in the system, but how long it can be found after use.

You already know that the potting effect usually wears off after a few hours at most. But THC remains on your system way beyond that. The “terminal half-life” of THC (how long 50% of the substance is naturally removed from the body) varies from one to two days for regular users and 3 to 13 days for normal users, depending on how strong the body’s acne is. It took five times as long to remove THC completely.

However, most companies do not test for THC (this test is expensive) but rather do a test for THC-COOH (or sometimes 11-OH-THC). The time it takes to detect THC and THC metabolites is very dependent on the type of drug test.

Urine analysis

This is the most common method employers use to test sweat. There are two different estimates from many reliable sources of how long it takes for the THC metabolite to appear in a urine test. This one from the Mayo Clinic is easy to understand if a little simple:

Random users:3 days
Moderate users:5-7 days
Daily users:10-15 days
Heavy user:30+ days
Table of how long cannabis is detectable in urine

An earlier study, conducted at the University of Missouri’s Laboratory of Toxicology and Drug Control, and regularly cited as the latest study, looked at two distinct breakpoints.

Most urine tests only show a positive result when the THC-COOH concentration is at least 50 ng / ml, as this is the government recommended level. The study shows that only heavy users can cross this limit for more than 30 days, and this only happens from time to time. Most chronic users pass the 50 ng / ml test in ten days or less. The researchers said these casual users would likely have no trouble getting a drug test within ten days.

Experts also see a stricter limit of 20 ng / ml, which is most commonly used by law enforcement agencies and employers as intolerant and harder to cross. At this level, THC metabolites can be detected for up to seven days in individual users and 21 days or more in chronic users.

Therefore, THC and / or metabolites such as TCH-COOH will stay in your system for more than 30 days if you smoke regularly and heavily. But they probably won’t be found in a month if you’re a heavy smoker, and they won’t be found in 10-15 days if you rarely use them.

THC Blood test
THC Blood test

Blood test

Fortunately, most employers don’t want to spend money on blood tests on their employees or applicants. Although THC is no longer detectable in the blood about five hours after each use, THC will build up over time in casual heavy users.

A study shows how long this problem can last. Participants were regular smokers but abstained for seven days – and at the end of that seven day period, about 25% still had detectable THC levels in their blood and 100% still had detectable THC-COOH levels.

In fact, THC-COOH testing is a more difficult problem for everyone. For casual but casual users, it can be found for up to seven days. In heavy users, it can remain in the body for a very long time and can be detected with a blood test 25 days or more after the user’s last smoking session.

The point here is easy to understand: if you are a daily user or a heavy user, you really don’t want to have any blood tests except for THC and not metabolites. Otherwise, just keep an eye on the windows for a week or less before you think you’re clean.

Hair and saliva test

The saliva test is more frequent than ever before, while the hair test is usually done to check for ongoing drug use rather than potty training. The good news for both is that there are a number of questions about its accuracy and reliability when using marijuana, so the results may not be as reliable as from a urine or blood test.

For casual users, THC will appear in a saliva test in about a day, and metabolites can only be detected in about three days. Heavy users had an even bigger problem when tested their saliva, which is based on the THC metabolite, which can remain detectable for nearly a month.

Hair tests show no evidence of recent first use for reasons that make sense if you think about it: it can take 7 to 14 days for new hair to grow from the scalp. But then THC-COOH can be detected for up to three months, as can the residual THC in heavy users. It is not clear whether THC in the hair of ordinary users can be detected reliably, because studies on the subject differ significantly.

How Long Does Cannabis Stay In Your System?
How Long Does Cannabis Stay In Your System?

How Long Does Cannabis Stay In Your System?

It should be clear that the amount you smoke, what strength you smoke, and how often you smoke will affect how much THC you absorb in your body and how long the metabolites remain in your system last.

Those who don’t smoke regularly and only take a few tokens just before their test may not have to worry, neither do those who take only a few edible bites. Judge smokers, daily smokers, or those who prefer and can afford the “good stuff” have a bigger problem when they put more THC into their system.

There are other factors that can also affect the levels of THC and THC-COOH in the body.

Body fat: TCH metabolites are stored in body fat. The more fat you have, the longer THC-COOH and 11-OH-THC will stay in your body and will be detected by testing. Users who are weak, low BMI tend to have a shorter test period to be concerned about. (Women usually have more body fat than men, so they are more likely to retain their metabolites for longer.)
Metabolism: Some people have faster metabolisms than others, and their bodies eliminate THC and its byproducts faster than people with slower metabolisms. This is very different from practice; Exercising right before the test can make you more likely to get dirty.
Hydration: There are many opinions about whether drinking plenty of water before a urine test will help you pass (it doesn’t hurt). However, research has shown that if you don’t drink enough fluids regularly and are dehydrated, your THC and THC levels can be detected, and COOH will rise.

This is a very long answer to a question that seems very simple. But like most weed enthusiasts, there really isn’t an easy answer – unless the question is, “Would you like to smoke a cigarette?”

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Published by Rickard Olsen

35 years and a journalist from Belgium and one of the founders of Cannabis News Europe. A Cannabis Activist for many years with multiple articles published in various magazines and newspapers around the world.

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