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How Long Does THC Stay in Your Body

How Long Does THC Stay in Your Body?

Most modern drug tests can detect not just THC but also its byproducts in the human body, but most forms of testing are not able to show how long it’s been since the person being tested actually smoked. This makes drug testing problematic even for those who live in areas where medical or recreational marijuana is legal. Job applicants and drivers, among others, are subjected to drug tests and if they have marijuana in their systems, it can cause all kinds of problems, even if the person has no intention of smoking before driving or heading to work.

It’s important for those subjected to routine drug tests, regardless of the reason, to understand what to expect. So, how long does THC stay in the body, and how long should marijuana users abstain? The answer is complicated, but this article explores some important details on the subject.

Factors that Influence Detection

While some drugs, like alcohol, completely disappear from the body after just a few hours of abstinence, THC and its byproducts can be detected for much longer. Exactly how long depends on several factors. They include frequency of use, the potency of the marijuana, consumption method, body composition, and the sensitivity of the drug test.

Frequency of Use

The average detection window for just one joint smoked on one occasion but someone who ordinarily does not use marijuana products is only around three days. That detection window grows longer the more frequently consumers smoke, though. Someone who smokes even a small amount of marijuana three to four times a week can expect most drug tests to pick up on it for at least five to seven days, and those who smoke at least once per day often find that they must abstain from all marijuana use for a month or more before it is completely removed from their systems.

Potency of the Marijuana

In this instance, potency refers specifically to how much tetrahydrocannabinol (THC) the marijuana has. Typically, the more THC a person consumes, the longer it takes for his or her body to break it down. There are also multiple factors that influence marijuana potency, ranging from the strain to the growing conditions, and more.

Consumers who buy their cannabis products from a licensed dispensary will usually be provided with literature describing each product’s characteristics, including its THC concentration. Those who grow their own marijuana can find information about strain genetics online and gauge where their buds fall on the potency scale based on when they harvested, how much attention their plants got during the vegetative and flowering phases, and how successfully the curing process went.

Generally, high-THC strains of marijuana produce more noticeable physiological effects than low-THC strains. Those who smoke strains high in cannabidiol (CBD) for medical reasons should note, however, that CBD affects how THC binds to the receptors in the endocannabinoid system, altering the level of psychoactive high experienced, but does not eliminate THC from the plant or the body unless the strain was specifically grown to be low-potency.

Those who use additional marijuana products such as hash, oil, and kief should note that since they contain higher concentrations of THC, it takes longer for the body to metabolize it fully. This is especially true of high-potency products like wax and shatter.

Consumption Method

The method of consumption also impacts how long marijuana stays in the system. Most consumers will already have noticed that when they smoke weed, they feel the effects almost immediately but when they eat edibles made with marijuana-infused oils, it takes between twenty minutes and three hours to feel the effects. The same applies to eliminating THC from the system.

When consumers smoke or vape cannabis, the THC should leave their systems roughly at the rates described above. If they eat it, they should expect the THC to linger in their systems for longer. Marijuana enthusiasts can learn more about how THC concentrations in the body vary depending to their consumption methods later in this article.

Body Composition

THC is lipid-soluble, meaning it binds to body fat. That’s part of the reason it can still be detected by urine tests weeks after the date of last consumption in any consumer. Those with higher percentages of body fat and/or lower metabolisms will find that it takes longer for their bodies to metabolize 100% of the THC they have consumed. As fat cells dissolve, the THC will be released back into the body, where it can then turn up on routine drug tests.

Lifestyle Factors

There are two lifestyle factors that can influence the results of marijuana drug tests. They are hydration and exercise. Dehydration increases a consumer’s chances of testing positive since it increases THC concentrations in the urine.

Heavy exercise immediately preceding the drug test can also increase the chances of testing positive. One small-scale study showed that 35 minutes of riding a stationary bicycle prior to testing increased the likelihood of positive test results for frequent smokers. The researchers have hypothesized that exercise causes fat cells to release their reserves of THC. This also means people with higher body mass indexes (BMIs) will see more significant increases in risk than people with less body fat.

Sensitivity of the Test

Not only do different types of tests have different detection windows, but even tests that use the same methodologies differ in sensitivity depending on the manufacturer. More about detection windows for different types of tests later, but for now, consumers should recognize that high-sensitivity tests can detect lower concentrations of THC. If a drug test is on the horizon, err on the side of caution and plan for the longest possible window of detection before consuming cannabis.

Types of Drug Tests

Urine tests are by far the most common type of drug test used by employers and others, not just for marijuana, but for all drugs. It’s not the only one, though, so it’s important for consumers to know what they’re up against.

Urine Testing

Since urine testing is the most relevant form of drug testing for most consumers, it’s a good place to start. The reason this form of testing is so popular is that urine tests are inexpensive to perform and have a longer detection window than most other forms of testing.

Urine tests don’t actually look for THC in the test-taker’s sample. Instead, they check for THC metabolites, or THC-COOH. This chemical is formed by the liver as it breaks down THC, and unfortunately, it remains in the body for longer than THC itself.

As a general rule, urine tests can detect marijuana in a consumer’s system for between 3 and 30 days after last use. The factors described above all play a role in determining how long urine tests are effective, though. Someone who has used marijuana only once can expect to test positive for between 1 and 16 days, while a frequent, heavy user should expect to test positive for at least a month after his or her last use.

Those with high levels of body fat and low metabolisms who use high-potency marijuana products multiple times per day should always err on the side of caution. The longest even a heavy pot smoker has ever reported testing positive after a period of abstinence is 45 to 90 days after last use. It may sound excessive to abstain from smoking for three months before a drug test, but for heavy smokers, that may be what it takes.

Saliva Tests

Saliva tests are only used infrequently to test for cannabis. They only detect THC for approximately 12 hours after a consumer’s last use. The flip side of that coin is that while urine tests typically don’t detect marijuana use for at least a day after consumers smoke marijuana, saliva tests show positive results within the hour.

Hair Tests

Hair tests are uncommon in today’s world because they are expensive and often inaccurate. Some employers still use them because they can detect the presence of THC and other drugs for much longer than urine, saliva, and blood tests. The detection window for hair tests is one week to 90 days, meaning that people who have smoked marijuana for the first time in three months less than a week before being tested will test negative.

As noted above, hair tests aren’t always accurate. It’s sometimes the case that THC doesn’t bind to the hair follicle, which means it can’t be detected. One 2015 study conducted by Friends Research Institute in Baltimore, MD showed that hair follicle testing correctly identified only 52.3% of self-reported recent marijuana users.

Blood Tests

Blood tests are only used commonly in one particular situation. Law enforcement officers use them to determine whether drivers are operating their vehicles under the influence. Unlike urine tests, blood tests don’t measure levels of THC byproducts, but the active THC itself. As a result, they’re only effective for three to four hours after last use, regardless of how frequently the driver had been smoking prior to that time window.

THC Concentrations by Consumption Method

As noted above, method of consumption affects how quickly THC enters the bloodstream and how quickly it is metabolized. Since most marijuana tests only provide positive or negative results and do not indicate concentrations of THC, the most important thing to consider is how long it takes for the body to metabolize THC and its byproducts completely. However, understanding the different detection windows for various drug tests requires a more in-depth look at THC absorption and concentration by consumption method.

THC Absorption When Smoking or Vaping

Smoking or vaping marijuana is the fastest way to introduce THC into the bloodstream. Most tests, with the exception of hair tests, can detect THC very soon after inhalation. Levels of THC in consumers’ blood typically peak just nine minutes after smoking and begin to drop off just 15 minutes after last use. Levels of THC in the blood will be significantly lower after just two hours.

The length of time that THC stays in the blood depends in part on how much consumers smoke or vape. Taking just one toke off a pipe or a joint will lead to THC levels dropping off significantly within just 3 to 12 hours. Higher doses of THC, such as smoking an entire joint or the better part of a blunt, will be detectable in the blood for up to 27 hours.

Keep in mind that frequency of use also impacts how long THC remains in the blood. Frequent smokers will have more THC in their systems upon consumption, so it will take longer for the body to metabolize it.

The reason concentrations of THC within the blood drop quickly after last use is that the compound is metabolized quickly by the liver. The metabolites produced during this process remain in the body’s fat cells for much longer. That’s what urine tests look for, and why they can detect marijuana use even weeks after the last of the THC has been metabolized.

THC Absorption When Eating

Ingesting marijuana edibles significantly alters how THC is absorbed by the body and how it is metabolized. Since the consumer’s body must digest the edible first, it can take several hours for noticeable amounts of THC to enter the bloodstream. The digestion process is slow, too, which means THC is introduced to the body more slowly and metabolized more slowly.

After eating an edible, active THC levels won’t drop to an undetectable level until around 25 hours after consumption. As with smoking, the byproducts produced by the liver as it metabolizes the THC will linger for much longer.

How to Pass a Drug Test

The only sure-fire way to pass a drug test after consuming marijuana is to abstain from use for at least a month. Not everyone has the luxury of waiting that long, though. There are tons of products on today’s market that claim to provide miraculously cleansing results even in heavy smokers, but unfortunately, most of them do not live up to the hype.

Detox Drinks

Just about every head shop in America carries at least a few brands of detoxifying drinks. Most of them are overpriced, though, especially given that they are glorified diuretics, and some of them don’t work at all.

As the market for detox drinks has grown, the drug testing industry has imposed countermeasures to combat their effectiveness. Consuming large amounts of fluids, especially diuretics, doesn’t generally lead to a negative test result. Instead, it leads to an inconclusive result, and test-takers are either penalized for attempting to alter their results or forced to retake the test.

Full Detox Programs

Detox drinks designed for same-day use are less effective and riskier than full-scale detox programs designed to speed up the body’s natural processes. Those who want to use detox drinks should start at least five to ten days in advance and should combine them with other measures such as exercising more frequently and avoiding foods high in fat, sodium, and sugar.

Get Plenty of Exercise

Both cardio and weight training burn fat and speed up metabolism. This helps to speed up the detox process, regardless of a consumer’s BMI. Make sure to shower after heavy exercise, since cannabis metabolites expelled in sweat can be reabsorbed through the skin.

Some people go the extra mile and wear heavy sweaters while they exercise to try to “sweat it out.” This technique is risky, as it increases consumers’ chances of heatstroke and dehydration. Plus, since only THC and not its major metabolites are excreted into sweat, it won’t make any difference once all the THC has been metabolized.

Don’t exercise heavily on the day of the test. The THC and cannabis metabolites released during exercise need to be expelled before heading to the testing facility.

Drink Tons of Fluids

While diuretic detox drinks can help, it’s important for consumers to drink plenty of water, as well. Diuretics leave people prone to dehydration and lower other key nutrient concentrations, so it’s important to supplement electrolytes by consuming things like sports drinks alongside water and detox drinks. Aim for consuming around a gallon of liquid per day and cut back on the last day before a urine test to ensure that it isn’t too diluted.

Eat Healthy Foods

Foods high in fat, sodium, and sugar can slow down consumers’ metabolisms, making it harder for them to rid their bodies of THC. Avoid junk food and red meats and focus on eating tons of leafy greens, fruits, vegetables, and fiber. This encourages the body to expel THC through bowel movements instead of urine.

Take Niacin Supplements

Niacin, also known as vitamin B3, promotes quick metabolism. It can be used prior to testing to help flush THC and its metabolites from consumers’ systems in advance, but it’s important not to overdo it. Overdosing on B vitamins isn’t fatal, but it can produce some unpleasant side effects such as nausea, vomiting, and rashes.

Bentonite Clay

There is some evidence that bentonite clay may help with THC detoxes. The clay contains molecules that are negatively charged, which causes them to bind with positively charged THC molecules. Bentonite clay can also boost metabolism and flush the metabolites released by fat cells during and after heavy exercise. Plus, it’s safe to consume, so while bentonite clay detoxes may not be 100% effective on their own, there’s no reason not to include it in a more comprehensive detox program.

Prepare on the Day Of

It’s best to schedule drug tests for the afternoon, not the morning, and to urinate at least a few times before providing the sample. On the morning of the test, consumers should empty their bladders as much as possible as soon as they wake up. Eat a large, healthy breakfast, and drink plenty of water but avoid over-the-counter detox products.

Home Detox Solutions to Avoid

While growing potent marijuana is often the goal when growing, there are times when individuals want the potency to leave their systems quickly. There are dozens of other supposed magic bullets for passing drug tests to be found online, but most of them don’t work and some of them can be downright dangerous. Drinking diluted bleach, for example, will not reduce THC or THC metabolite concentrations, but will absolutely place consumers at risk of serious health complications or even death. Not only is bleach toxic when ingested, but it contains no ingredients that bind to THC or its metabolites, inactivates them, or otherwise produces negative results.

The second solution best avoided has nothing to do with detoxification. Some heavy users purchase synthetic urine online or even attempt to substitute other solutions like chicken broth. It’s absurd to assume that a highly trained lab technician would be fooled by fake urine, so save the money and avoid the legal hassles associated with these supposed quick fixes.

Know What to Expect

Home testing kits are widely available both online and in head shops. Cannabis consumers can use them in advance of their official urine tests to make sure they will pass. Even those who are pretty sure they will pass can benefit from ordering home tests. If nothing else, it will give them the peace of mind of knowing what to expect.

Those who have been heavy-duty detoxing for a week or more should be in good shape, especially if they’re only infrequent consumers. Test takers who want to use methods like urine dilution or same-day detox drinks should find out what a positive or inconclusive result will mean for their futures. Inconclusive test results typically just lead to a second test, but in some cases, two or more inconclusive results may be treated as a positive. Know what to expect before resorting to high-risk detox methods.

The Bottom Line

The only sure-fire way to pass a drug test is to abstain from using drugs. In the case of marijuana, that means a month or more of abstinence for regular users. Many marijuana enthusiasts are unenthusiastic about taking a total abstinence approach to detoxing, which is understandable. They should still prioritize quitting smoking for at least a week and use the methods above to create a safe and effective detox program to maximize their odds of getting negative results.

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