Fraser Horton
Fraser Horton
Last Updated on August 28, 2021

When using marijuana, whether recreationally or medically, its effects can last for three to eight hours, depending on the methods of consumption. But even after the effects wear off, marijuana stays detectable in the body for days, even weeks after use. The amount of time that it takes for THC to be processed and eliminated from the body depends on many factors.

Due to cannabis consumption being so common nowadays, drug testing in the workplace has become a common practice as well. This is why many users are curious to know how long THC stays detectable in the body, which is what we’re going to cover today.

What Happens to THC in the Body When You Inhale or Ingest Weed?

THC (delta-9-tetrahydrocannabinol) is the psychoactive cannabinoid that produces feelings of relaxation and euphoria, otherwise known as getting high, which makes it the most sought after cannabinoid, especially by recreational users. When you consume marijuana, whether through inhalation or ingestion, THC undergoes many processes that give us insight into how long it stays detectable.

When you inhale weed, whether by smoking or vaping, THC enters your bloodstream through your lungs in a matter of minutes and it starts circulating throughout the body, producing its effects. It takes only a few minutes to get high when you inhale weed. After a while, THC travels to the liver along with the other cannabinoids, where they get metabolized into byproducts so that the body can eliminate them more easily.

Things are different when you ingest weed because THC has a different route of absorption. When you eat an edible, it has to be processed in your digestive system first, just like any other food. THC then gets sent to the liver where it’s partially metabolized before it re-enters the bloodstream, travels to the brain, and starts producing its effects. This is why edibles take much longer to kick in.

Whatever the method of consumption, THC ends up in the liver and gets metabolized into dozens of byproducts that get stored in the fatty tissues because, just like THC, they’re fat-soluble. THC-COOH is the most important THC metabolite because it’s what most drug tests look for. 

Finally, the THC metabolites are gradually converted into water-soluble compounds so they can be eliminated from the body through urinary and fecal excretion.

How Long Is THC Detectable in Urine?

The urine drug test is by far the most commonly used drug test in the workplace as per the recommendation by the Substance Abuse and Mental Health Services Administration (SAMHSA). It’s non-invasive, fast, affordable, and fairly accurate. 

The urine test is designed to detect the THC-COOH metabolite at a cutoff concentration of 50 ng/ml (nanograms per milliliter). That means that any value at or above this number will produce a positive result. If your urine sample tests negative, that would mean that the THC concentration wasn’t high enough to be detected. The samples are usually tested twice, once for initial testing, and the second time is confirmatory testing in order to avoid false positives.

That being said, how long THC will remain detectable in urine depends on many things (more on that below), but it’s primarily up to the weed habits of cannabis users. Generally, the more frequently you use weed, the more THC metabolites accumulate in your body. The THC-COOH metabolite is quite stubborn and has an unusually long half-life, making it harder to eliminate in a short period of time. That’s why a full detox is usually encouraged at least two weeks before the test.

The detection window of urine tests, which is the length of time a substance can be detected in the urine, predominantly depends on the frequency of your marijuana use:

  • Occasional marijuana users (up to three times per week) – up to 3 days;
  • Moderate users (a few times per week) – 5-7 days;
  • Chronic users (every day) – 10-15 days;
  • Heavy users (multiple times per day) – more than 30 days.

If you’re preparing for a drug test, there are at-home THC test kits that you can use to check the THC levels in your urine sample. Though please note that these kits are not as sensitive as the tests used in labs.

Finally, if you’re taking full-spectrum CBD products, it’s unlikely that the THC levels will be high enough to be detected by the test as CBD products only contain trace amounts of THC.

Different Drug Tests Have Different Detection Windows for THC

Apart from urine tests, there are also other types of drug tests used in the workplace or elsewhere and they all have different detection times. Similarly, they all have different cutoff levels. Some of these tests detect THC metabolites, while others look for THC itself.

Hair Test 

The hair follicle drug test is known as the most accurate test with the longest detection window because it can detect habitual weed use for the past 90 days. Like the urine test, the hair test also looks for the THC-COOH metabolite.

Blood Test

Compared to other types of drug tests, blood tests have a much shorter detection window, usually up to 36 hours. Blood tests aren’t used in the workplace and are most commonly employed to demonstrate current impairment, rather than habitual or recent drug use. Unlike urine and hair tests, blood tests don’t look for THC metabolites, but THC itself.

Saliva Test

Similarly, the saliva test (or oral fluid test) also detects the parent drug (THC) instead of the metabolites. The saliva test also has a short detection window of up to 72 hours, but it can be used in some fields of employment.

Factors that Determine How Long THC Stays in Your System

There are a number of factors that determine the half-life of THC, which is the amount of time required for half of the body’s absorbed THC to get completely eliminated – and most of them are subject to the weed habits of the users themselves.

Frequency of Use

The frequency of your cannabis use will inevitably impact how long THC will remain detectable in your system. Chronic users who consume weed at least once a day will have a higher concentration of THC metabolites because their bodies will be saturated with cannabinoids (they will also take longer to detox). In contrast, infrequent users will clear THC from their bodies in less than a week, or at least the THC levels will be low enough to be undetectable.

The Strain

What strain you use is another important factor. Typically, strains with high THC levels and low CBD levels produce more THC metabolites. On the other hand, if you choose to use a strain that’s higher in CBD, it will give your body less THC to metabolize (which means that the metabolites will clear faster). 

Dosage

The amount of THC you consume also impacts how long THC will stay in your system. Similar to the frequency of use and the potency of the strain, if you consume larger amounts of weed, it will result in more THC metabolites stored in your cells.

Metabolism

Your metabolism is one factor that’s not always subject to your personal preference. Each person has a different metabolic rate which also determines how fast it will eliminate toxins and byproducts from the body. Your metabolism rate is largely determined by genetics, but sex, age, lifestyle, physical activity, and some health conditions definitely have an impact.

Body Fat

It’s believed that the more body fat you have, the longer marijuana stays in the body because THC metabolites are fat-soluble and bind to the fat cells. Therefore, for people with a higher body fat percentage (BMI, or body mass index), THC can stay in the body for a longer period of time compared to users with a lower body fat percentage. However, it’s also important to note that there can be exceptions to this as everyone’s body works differently.

Genetics

Genetics can also have an impact on how long THC will remain in your body. This is largely connected to the superfamily of enzymes in the liver that are responsible for breaking down THC. It has been observed that some of these enzymes have different genetic variants that influence how fast or slow your liver will metabolize THC.

Conclusion – How Long THC Will Stay Detectable in Your Urine Depends on Many Factors

Weed stays in the body long after its effects have subsided, which is why it can be detected by drug tests for days and weeks after last use. When you consume weed, it gets broken down into many byproducts in the liver that get stored in the fat cells in the body and are slowly released over time to be eliminated through urine and feces. 

The urine drug test looks for these metabolites because they take a while to leave the body. Other types of drug tests may either look for the metabolites or look for the parent drug itself and they all have varying detection windows.

How long THC will stay detectable in your urine depends on many factors, of which the frequency of use, the dosage, and the strain may be the most important ones because they depend on the user’s personal preference and weed habits.

Disclaimer

The information presented on this page is provided as a public service to aid in education and is derived from sources believed to be reliable. Readers are responsible for making their own assessment of the topics discussed here. In no event shall Leaf Nation be held reliable for any injury, loss or damage that could happen if using or abusing drugs.