Surprise Drug Test! How Long Does Weed Stay in Your System

jar of weed

Way too many of us experienced this situation — we decided to spend the weekend toking up and getting all nice and high with friends.

You think it’s no big deal because you have been with this job for a long time and were only drug tested when you first started.

Until — uh oh! You walk in Monday for a surprise drug test. You do the test, hoping all of that marijuana is out of your system. Well…is it? There are many myths revolving how long cannabis stays in your bloodstream.

So, how long does weed stay in your system? Here’s what you need to know.

How Your Body Metabolizes Marijuana

Before we describe how long marijuana stays in your system, it’s important to know how it’s metabolized.

THC is the psychoactive cannabinoid that shows up on drug tests. After you smoke or ingest cannabis, your body absorbs the THC in your bloodstream.

From here, THC binds to your CB1 receptors and transports to the vital areas that THC effects, such as the brain and the nervous system.

Even though you only feel the THC effects for a few hours, the cannabinoid is stored in your body. That’s because marijuana is a lipophilic substance, or it binds with fat.

That’s why THC can be stored in your fatty tissue but also your organs, muscles, spleen, kidneys, and liver. It can even be reabsorbed in your bloodstream. This takes longer for your body to rid the THC out of your system.

When THC is finally ready to be metabolized out, it’s broken down in the liver.

This helps THC metabolize in several metabolites. These metabolites last longer than the THC does itself. It’s the metabolites that usually appear in a drug test result.

How Long Does Weed Stay in Your System? It Varies

The shortest answer is, it varies. That’s because many factors go into the way the cannabinoids are metabolized. It also varies with each drug testing method, which we will go over momentarily.

Here are factors that determine how long marijuana stays in your system.

  • Your tolerance
  • How much marijuana you last consumed
  • How you consumed marijuana (smoked, ingested, etc.)
  • Your health
  • How much water you drink
  • The strength of the strain
  • Your BMI

Here’s a breakdown of how these factors contribute to how long marijuana stays in your system.


Your BMI, or body mass index, affects how long cannabis stays in your system. This is a measurement of body fat based on your physical characteristics and has to do with the way your body metabolizes cannabis.

Many factors contribute to your BMI. This includes:

  • Height
  • Weight
  • Age
  • Gender
  • Ethnicity
  • Muscle Mass

In short, those with a smaller BMI metabolize THC quicker than those with a higher BMI. If you have higher fat, it’s likely the THC will be stored in your body for longer and will take slower to metabolize.

However, this isn’t the only and usually is not the most reliable factor when determining how long THC stays in your system.

The Strain

More potent marijuana strains contain more THC. In short, the more THC you consume, the longer it will take for your body to rid itself of the THC. How much is a lot of THC? Assume strains with at least 25% of THC are on the potent side.

How Much Marijuana You Smoke

If you smoke a lot every day and primarily smoke potent marijuana strains, it will take longer for your body to fully metabolize the THC. How much is “a lot?” At least one joint every day.

How You Consume Marijuana

The last two points also boil down to how you take THC. The two most popular consumption methods are smoking and ingesting.

Do you notice it takes longer to feel the THC effects when you eat an edible, but the effects are intense?

The edible has to make it through your digestive system in order to experience the effects. But you absorb more THC into your bloodstream than when you smoke it.

This is why marijuana lasts longer for those who regularly eat edibles as opposed to those who regularly smoke marijuana.

How to Beat a Drug Test

If you have a big job interview coming up or don’t want to be caught with a random drug test, there are ways you can beat a drug test. Here are a couple of methods.

Cleansing Your System

If you suspect your upcoming drug test will test your urine, you can cleanse your system in hopes no THC metabolites come up in your urine. Do this by drinking copious amounts of water or drinks packed with vitamin B12.

Keep in mind, it takes a long time for THC metabolites to leave the urine — even over two weeks for a light user! This method isn’t the most effective but it’s worth a shot.

Being Sneaky

Unfortunately, the only other real option is being sneaky and fooling the test.

The most common methods are receiving a test result saying you false passed (you’ll have to find specialty products for this), using someone else’s urine/hair/blood, and adding other substances to your urine/hair/blood.

Other Substances That Can Appear on a Drug Test

Do you not smoke marijuana but use other substances that can appear on a drug test? Here are some other substances that your employer may pick up.


For moderate drinkers, alcohol only stays in your urine for an hour and a half. But heavy drinkers and those extremely drunk can hold alcohol in their urine for up to 12 hours.


This depends on the user, their last dosage size, and how frequently they use it. On average, a laboratory can detect cocaine in your urine for two weeks after last using the drug.


If you abuse pills, testing for pill use isn’t as reliable.

That’s because prescription pills metabolize similarly to “bad drugs” — for example, opiates and heroin. If you have a prescription for your pills, always show the prescription to your employer before taking the test.

Party Drugs

Party drugs such as ecstasy only last three or four days in your urine.

Kratom and Kava

Kratom and kava are two beverages made from plant extracts that produce stimulating effects.

On average, kratom only lasts a little over a day. Kava lasts as little as nine hours. If you suspect your employees are using kratom, view here.

Do You Smoke Weed Anyway?

How long does weed stay in your system? Are you the kind of stoner who doesn’t care and just wants to roll another blunt? Visit our cannabis section — only if it’s legal in your area.