How Long Does Marijuana Stay in Your System?

Marijuana is known to be beneficial in the treatment of some conditions, but it could potentially cause side effects to a few people such as depression.

If you are using marijuana and going to have a drug test, you may wonder how long it’s going to stay in your body. With our guide, you will finally know all about the factors that influence how long weed stays in your blood, urine, saliva, and hair.

Before we answer the main question, it is important to understand what makes weed traces in your body stay longer. Here are the 5 major causes that may influence the amount of time that THC will stay in your system:

1. Dosage

Of course, the larger the amount of marijuana you consume, the longer it will take the body to break it down. From there, your system will have to work through its corresponding metabolites during a certain period of time in order to remove any remaining trace of the consumed THC.

2. Regularity of Marijuana Use

The frequency of use has a substantial influence on how long weed will be in your system.

Most research on cannabinoid detection showed that THC stays in the system of long-term users far longer than one-time or occasional users. Moreover, long-term and high-frequency cannabis use can become an important factor in developing cannabis withdrawal symptoms.

Indeed, the latter begins when a long-time user suddenly stops marijuana consumption, which can cause anger and even in some cases, depression.

3. Genetics

Genetics also influences the time THC remains in your system. For example, people who inherit different variants of enzymes (cytochrome P450 superfamily) can have an easier time than others in modifying THC levels in their body, which results in its elimination through urine.

4. Fat

The quantity of fat in the body is also a significant factor. People with higher body fat % may metabolize THC a bit slower than a person with less body fat. In the same vein, working out can also influence the levels of detectable THC metabolites. Once the fat is burned, dormant THC from fat will be released into the blood. Thereafter, it will be excreted from the body in urine or feces.

5. Metabolism

If your body has rapid metabolic functions, it should be able to break down cannabinoids at a faster rate than the average. In other words, it will reduce the period that THC will remain detectable in your body.

How Long Does Weed Stay in Your Blood?

In the act of smoking weed, active THC can be found in the bloodstream in just seconds. Furthermore, THC can be detected for several hours which depends on the dosage and periodicity of use.

According to a 2004 study published in Therapeutic Drug Monitoring, the plasma concentration of THC climaxes just 3-8 minutes after inhalation and then drops about 30 minutes after.

The study also claimed that THC is detectable in blood for approximately 5 hours, but the THC left in the metabolites has a lasting time of up to 25 days.

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How Long Does Weed Stay in Your Urine?

Urine screenings are usually used as a standard to detect cannabis use. Most urine tests utilize specific responsiveness for the cut-off concentration of THC.

Plus, the usual cut-off concentration point is 50 nanograms per milliliter (ng/mL), as considered by the Substance Abuse and Mental Health Services Administration (SAMHSA). A 2005 study by the National Drug Court Institute reported that THC detection times rarely exceeded 30 days.

Here’s a rundown of the different things the study confirmed:

  • Using the suggested cut-off concentration point (50 ng/mL), the study found that it is improbable that a chronic cannabis user will have detectable THC metabolites in their urine after 10 days from their last smoking session.
  • At the lower more sensitive cut-off concentration point (20 ng/mL), it was found that the metabolites in chronic cannabis users could be detected for up to 21 days after THC consumption.
  • For one-time users, the same study also found that with a 20 ng/mL cut-off concentration point, it was unlikely for a drug screening to detect THC metabolites in urine after 7 days.

Another study from Mayo Clinic Proceedings in May 2017 stated that weed can be detected in urine:

  • Up to 3 days in occasional users
  • Up to 5-7 days in moderate users
  • Up to 10-15 days in daily users
  • After more than 30 days for chronic users who consume several times a day

How Long Does Weed Stay in Your Saliva?

According to a 2014 study reported in Drug Testing and Analysis, the researchers looked at cannabinoids in oral fluid. Then, they found that different marijuana users had THC metabolites detection in their saliva:

  • In occasional users: 1-3 days
  • In chronic users: up to 29 days

How Long Does Weed Stay in Your Hair?

Some people may think that hair follicle drug testing methods won’t be able to precisely detect weed. However, a research published in Scientific Reports found that the presence of THC and THC metabolites can be transferred to the hair follicles of non-users through contact with:

  • Hands
  • Sweat
  • Exhaled smoke

The study also found that, after giving participants 50 milligrams of THC for one month, the hair follicle drug test’s effective lifespan is much longer than with urine and blood tests, sometimes detecting the existence of THC up to 90 days after use.

Furthermore, a 2017 study in Drug and Alcohol Review analyzed hair samples gathered from 136 subjects and found different detectable levels of THC:

  • 77% in chronic users
  • 39% in light users
  • 0% in non-users

The study showed that the chance of having THC found in hair samples relates to increased frequency of use.

In conclusion, all these factors can affect how long weed can stay in your system. Plus, it can possibly stay longer depending on your body mass and fat %, as well as your metabolism.

Lastly, we recommend not smoking weed nor staying with a weed user for at least 1-2 months before doing a drug test. That way, you will have a better chance to pass the test.