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How Long Is Weed In Your System For? (Everything You Need to Know)

As a consumer of medical or recreational marijuana, you may be wondering how long is weed in your system for. We’re answering that and other questions here.

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how long does thc stay in your system calculator

Whether you’re looking to pass a drug test or are simply curious about the long-lasting effects of medical marijuana, find out how long you can retain weed in your system.

It would be great (and helpful) if there were a cut-and-dry answer that applied to everyone. Yet, the reality is that everyone’s system processes marijuana uniquely. As such, there’s no exact timeline that defines the length of time the herb stays in your body.

Yet, advancements in technology have made it easier than ever to investigate how our bodies absorb and break down marijuana. This has led to more accurate analyses that can help you plan ahead before you make your next move.

In addition, as testing procedures become more sophisticated and refined, we’re given a clearer look into what the detection window looks like, and when it closes.

We’ll look at several key findings that give a better picture of how long in can stay in your system.

Ready to learn more? Let’s get started!

Testing and THC: Understanding the Basics

If you’ve ever smoked marijuana, you may be familiar with its ability to alter your state of consciousness.

Cannabis has this effect due to the presence of a chemical known as tetrahydrocannabinol, or THC. This is in the family of compounds known as cannabinoids. This chemical is found in the resin that the cannabis plant‘s glands produce.

Our brain has many cannabinoid receptors. They control our memory, pleasure, concentration, coordination and more. When THC attaches to these receptors, it affects our ability to control these functions.

When wondering how long you’ll keep weed in your system, it’s important to understand the important role that THC plays in this determination. Depending on how your body metabolizes the chemical compound, you could still test positive for cannabis days after someone else is cleared.

One of the main reasons why? If you’re a frequent smoker, you’ll actually store up THC in your system, building a tolerance. This means that you’ll have weed in your system longer than someone who’s only an occasional smoker.

The presence of THC is also known to be higher in certain types of testing than in others. So, depending on your selected method, your THC levels could be elevated over another testing procedure.

Below is a handy breakdown of how long THC will stay in your body. This is calculated around how frequently you light up, and the methods that each specific test requires.

weed in your system

Urine Analysis

This analysis involves providing a specimen of your urine to be tested for the presence of alcohol or drugs.

Urine tests are the main drug testing procedures recommended by the Substance Abuse and Mental Health Services Administration (SAMHSA).

It’s important to remember that these tests aren’t just seeking to determine whether you’re currently under the influence. Rather, most are also designed to pick up on traces of the drug that could remain in your system from use days earlier.

In this case, the urine analysis isn’t looking for THC chemical itself. Rather, it’s looking to see whether or not your body has created THC-COOH.

This is a metabolite that forms in your body after you consume marijuana. Detecting it will reveal your body has processed the cannabis. These metabolites can stay in your body long after the smoke clears without impairing you.

General Rule of Thumb

As a general rule of thumb, THC metabolites will remain in your urine for five to eight days if you’ve only used marijuana once. However, as mentioned, if you smoke more often, you’ll have weed in your system for longer.

If you smoke a few times each month (around two to four), the metabolites could remain in your urine for around 11 to 18 days. Then, it only goes up from there.

For instance, a smoker who partakes around five to six times per week will retain THC-COOH in his or her urine for up to 48 days. If you’re a daily user, a urine test could read positive for up to 63 days.

A typical urine test has a cut-off limit of around 50 nanograms per milliliter (ng/mL). However, some employers may opt to go lower, creating a limit of around 15 ng/mL, or higher, allowing up to 100ng/mL.

Saliva Testing

Another way to test whether someone uses marijuana is through a saliva test. Though this isn’t as common in the workplace, it’s one of the primary ways roadside police will conduct on-the-spot drug testing.

Unlike in urine, THC-COOH can only live for a short while in your saliva. Specifically, the metabolites will first show up about one hour after you smoke and could stay alive for up to 24 hours in your mouth. Even if it’s your first use.

If you’re a seasoned smoker who does so frequently, THC-COOH could stay in your saliva for up to 72 hours. Even up to a week if you partake in heavy marijuana use.

While this is a significant time, it’s a lot less than the duration that THC-COOH stays at a detectable level elsewhere in your body.

Hair Follicle Tests

Though their use and accuracy have been debated, hair follicle tests are still used by many employers, often offered through private testing agencies.

The sample of hair will be taken relatively close to your scalp and will give testers a look into what you’ve consumed over the course of around 90 days. Typically, testing is conducted on the first 1.5 inches of your hair.

The reason why this location is optimal for testing is that hair grows from the root down, and as such, this can ensure a recent, healthy sample.

Overall, hair follicle tests typically have the longest detection window of any of the other tests.

For these types of tests, it’s helpful to understand that THC metabolites will begin to show up in your hair around seven days after you consume the cannabis.

Though most hair follicle tests are performed on the scalp, there may be some performed using body hair.

While there haven’t been many conclusive studies done on the presence of THC metabolites in body hair, some data suggest that they may linger for up to a year or so, as this type of hair is less frequently shed.

Blood Tests

While hair testing for cannabis isn’t too common, neither is blood testing. However, it is becoming a more widely accepted way for cops to test for weed in your system.

To this end, THC-COOH can be found in your blood for up to 24 hours if you’ve only smoked once and up to one week if you’re a heavy user.

As such, blood tests are most commonly used to determine if someone has smoked marijuana recently, rather than to detect if that person is a long-term user. This explains why blood testing is another method being investigated more widely for use in police interrogation.

Sweat Tests

Though employers have traditionally depended on urine, saliva, blood, and hair follicle testing to determine if an employee is abusing drugs or alcohol, some are opting to forego these more traditional testing procedures in favor of less-invasive sweat tests.

In these tests, a user wears a patch over a part of his or her skin. The patch stays for about a week and a half or two weeks. During this timeframe, the patch absorbs sweat on your body to determine if you have weed in your system.

Though results are inconclusive, research reveals that frequent marijuana users will secrete THC chemicals at a rate of around 1ng per patch, which could continue for weeks after use.

Got Weed in Your System? Why It’s Hanging Around

Now that we’ve gone over how long you can keep weed in your system, and which parts of your body retain it the longest, you might be wondering why it stays in your body at all.

After all, you can metabolize a large glass of wine in about three hours, and health professionals agree that alcohol can stay in your urine for up to 48 hours, your breath for 24 hours, and your hair for 90 days.

So why the discrepancy between the way you store weed in your system and the way you process alcohol?

The answer lies in the way THC is stored in your body. As a cannabinoid, this chemical compound is fat-soluble. Thus, as it creates metabolites (THC-COOH), they enter your fat cells, where they’re stored and eventually diffused into your bloodstream.

This explains why someone who smokes marijuana heavily can keep levels of THC-COOH up longer than someone who smokes only once, or on occasion. The metabolites are actually storing up in that person’s body, and as such, their active compounds are likewise growing.

To put this idea in perspective, researchers recently discovered that THC was located in biopsies of rodents’ fat cells up to 28 days after consumption.

Exercise and THC Levels

Another factor that can determine how long you’ll keep weed in your system is exercise frequency, and the exertion you put forth when you do.

Scientists recently discovered a link between THC concentrations and exercise, especially in heavy users. They came to this conclusion after studying the way that rodents reacted to ingesting marijuana, then exerting physical activity.

They found that when regular cannabis users work out, they release stored THC from their fat stores and excrete toxins through perspiration.

On the other hand, someone who rarely works out reduces his or her potential to burn fat. Providing a greater opportunity for THC to bond with those fat cells.

Likewise, if your BMI is on the high scale and you have a significant percentage of fat on your body, you could be at a greater risk for storing weed in your system longer than someone who burns the appropriate number of calories daily.

Moreover, be sure to drink plenty of water if you’re looking to get rid of the weed in your system. Studies reveal that dehydration actually causes your urine to become more concentrated. Thus increasing your chances of a positive result.

Keep in mind, however, that drinking too much water could render your sample unusable, and force you to retake the test. So drink up, but be careful!

Helpful Reminders to Keep in Mind

The above guidelines are meant to serve as high-arching overviews of how long you can expect to keep weed in your system, or in this case, THC and its associated metabolites.

As you research further, remember that each person is different. Thus, internal and external factors such as metabolism, diet, and lifestyle play a role in how quickly, or slowly, you process the chemicals.

That means that even if you only smoke occasionally, but have a more sluggish metabolism, you could take longer to test negative on a drug test than someone who’s a chronic user with speedy metabolic processing.

Your levels will also vary depending on the type of test and the method being used to conduct it. For instance, THC-COOH is more frequently found in urine than in saliva, because it lives longer in urine.

Your Next Step: Consult with a Cannabis Expert

Are you looking to learn more about how to navigate the cannabis industry? If so, we’d love to help.

Our cannabis consulting firm will walk you through every step of the journey. We’ll help you acquire the permits, talent, and training you and your teams need to succeed in this growing market.

Whether you’re a company looking to become a license holder, or an investor looking to cash in on everything this hot opportunity has to offer, we’ve got your back.

Feel free to browse our services and contact us with any questions or ideas. Let’s take that first step in partnership together!

Have a drug test coming up for that new job you just landed but are worried you might not pass?  Fear not, we have you covered.  Click the link below:

How to pass a urine drug test

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How to Take CBD Oil as Medication

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How to Make Pot Brownies – Part 1


About Quantum9

Quantum 9, Inc. is a Chicago, IL-based cannabis consulting firm. We specialize in getting high net worth individuals and private equity cannabis business licenses to cultivate, manufacture and dispense marijuana. We have over 50 marijuana consultants that work for the company, and we have practiced in 12 countries. Our areas of expertise include permit acquisition, team building, employee training planning, and process planning. We help clients fully maximize the potential of any cannabis cultivation, processing, and dispensary business.


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