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How Long Does Weed Stay In Your System 2024? What You Should Know

Teresa Mboci

Reviewed by Brittany Ferri, PhD
how long does weed stay in your system
Weed can stay more than 30 days in your body. Photo: Nghi Tran

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In countries where marijuana is not legal, failing a drug test can result in a variety of negative outcomes, including disqualification or termination of employment, as well as legal consequences.

If you’re concerned about passing a drug test, here’s what you should know.

Marijuana is a highly contentious natural remedy with both medicinal and recreational applications. Recreational marijuana, on the other hand, is illegal in the majority of countries, and the legal consequences can be severe.

Understanding how marijuana is processed in the body and how drug detection works can help you avoid failing a drug test.

This article contains all the information you need to avoid failing a drug test, including the factors that influence the likelihood of detection and how to get weed out of your system.

How Long Does Marijuana Stay In Your Body?

Weed can stay in your system for 30 days or more. However, some factors influence the rate at which weed is excreted from the body.

How Long Does Weed Stay In Your System?

About 15% of the weed remains in the body,[1] while 20% is excreted via urine and the rest via feces.

THC is stored in body tissues and organs such as fat, the brain, and the heart. It eventually returns to the bloodstream and is metabolized in the liver, where it is converted into 11-hydroxy-THC and carboxy-THC. 

THC accumulates in fat tissues faster than it can be metabolized in marijuana users, making it easily detectable.

It can be detected within 3 days of use for first-timers and individuals who only take it on occasion.

Average smokers who use marijuana on an irregular basis may fail a drug test if it is administered within 5 to 13 days of use.

Weed can stay in your system for 30 days or more. However, a number of factors influence the rate at which weed is excreted from the body.

Understanding Weed

Weed, also known as pot, marijuana, or simply cannabis, is a natural psychoactive substance that causes euphoria and has both beneficial and harmful effects on your overall health.

Cannabis sativa and cannabis indicia are two species of herb. Weed can be consumed in a variety of forms, each with a different rate of absorption into the bloodstream and effect. Trichomes, or glands on marijuana flower buds, produce an oily substance that transports the active compounds in marijuana. 

THC is the primary psychoactive substance in marijuana that causes the “high” sensation. Cannabinoids, or plant constituents, include cannabigerol (CBG) and medicinal cannabidiol (CBD).

Cannabis can be detected in the body even 30 days after smoking, depending on a variety of factors, the most important of which is the frequency of consumption.

How Is Weed Detected In The Body?

blood test
Blood test lasts up to 12 hours after weed consumption. Photo: angellodeco/Shutterstock

Weed drug testing entails collecting samples and testing them. Your medical provider may test the concentration of THC in your body using urine, saliva, hair, and blood. Each of these tests has a different level of accuracy and time frame within which it should be performed.

  • Blood Test: Blood tests have the shortest detection time, lasting up to 12 hours after weed consumption.
  • Saliva Test: Most saliva tests can detect marijuana addiction within 24 hours of consumption. However, on rare occasions, they can detect it after 72 hours.
  • Urine Test: Urine testing can detect marijuana up to 30 days after it has been consumed. The most common drug test is a urine test.
  • Hair Test: The hair test is the most sensitive because it can detect weed in passive smokers or people who have had contact with a weed user. Examiners test to detect THC in skin oil that ends up in your hair. Hair tests can sometimes result in a false positive. A hair test can detect marijuana up to 90 days after consumption.

Factors That Influence Detection


Regular THC use increases the likelihood of detection because weed accumulates in body tissues and organs.

Type Of Sample Tested

Hair and urine tests, which are more sensitive than saliva and blood tests, can detect smaller amounts of marijuana.

Potency Of The Weed

The amount of THC in a specific amount of weed determines its potency. Because drug tests measure the amount of THC in the body, consuming more potent weed increases the chances of detection.


Metabolism aids in the elimination of THC and other body chemicals that have come into contact with the substance. As a result, people with faster metabolisms have lower THC levels.

Body Fat

THC in marijuana has a tendency to accumulate in body fat. As a result, people with more body fat tend to metabolize THC at a slower rate than leaner people.


Females have more fat mass than males, making them slower to metabolize THC than their male counterparts.

Physical Activeness

physical activeness
Exercising raises THC concentrations in the body. Photo: muse studio/Shutterstock

According to this study,[2] exercising temporarily raises THC concentrations in the body, increasing the likelihood of detection. According to the researchers, calorie-burning causes fat cells to release their THC content, resulting in an increase in THC concentration.


Although proper hydration does not increase your chances of passing a test, extreme dehydration raises the concentration of THC in the body, increasing the likelihood of detection.

How Can You Dispute A Failed Drug Test?

Because drug tests are only partially accurate, you can always request a retake. You should also inform your doctor if you consume any other foods, vitamins, supplements, or prescription drugs that may be interfering with the results.
If you abuse a substance, it could be best to come out before taking the test.

How To Get Weed Out Of Your System?

Fortunately, high doses of aspirin may reduce the accuracy of a urine test for marijuana smokers. You should also avoid submitting urine samples in the morning because metabolites tend to accumulate during sleep

Because drug tests look at the concentration of THC in your system, you should focus your efforts on diluting the drug concentration in your sample.

Increasing your water intake and frequency of urination can help, but only marginally. However, it is recommended that you fill your bladder with as much fluid as it can hold 1 or 2 hours before the test.

If your drug test isn’t coming up soon, you can control the main factors that influence your THC concentration, such as metabolism, body fat, dosage, and weed potency. This boils down to reducing your weed consumption and maintaining a high metabolism rate through regular exercise.

Can Any Substance Other Than Marijuana Affect My Drug Test Results?

If the purification process is ineffective, you may test positive for taking CBD products derived from the marijuana plant.

Some supplements may also contain CBD oil containing more than 3% THC, which will result in a failed drug test.

If you are currently taking nausea and chemotherapy medication, you may fail a drug test.


The main takeaway is that THC has a cumulative effect, so knowing when to quit weed before a drug test can mean the difference between passing and failing.

Proper hydration and exercise are also important in increasing your chances of passing the test because they affect the concentration of THC in the body and increase THC metabolization.

If you are not using, inform your examiner about all of the medicines, herbs, and supplements you are taking, including prescription and non-prescription drugs.

Frequently Asked Questions

What makes a urine drug test positive?

A urine drug test can emerge positive if the THC content in your urine exceeds 50 nanograms per milliliter (ng/ml). People who use marijuana may pass a drug test on rare occasions if their THC content does not exceed this level.

Can failing a drug test affect my employment?

In most cases, failing a drug test automatically translates to disqualification. But if you are already hired, some employers may decide to continue working with you, but deny promotion until you pass future drug tests.

Are there any special conditions under which you must take a drug test?

Urine tests are the most common drug test, in which case the examiner might demand that you take the sample in the presence of a witness.

What causes a false positive drug test?

Most over-the-counter drugs contain amphetamine and methamphetamine which are the most common causes of false positive drug tests. You can also fail a drug test for consuming foods that contain similar chemical compounds to prescription and illicit drugs.

Can a test show how high I am?

No. Currently, there are no gadgets for telling whether you are “high” on marijuana. But there has been increased investment in the innovation of such technologies, especially for enforcing safety standards in countries that have legalized weed.

Can an eye test detect my smoking habit?

No. Eye examinations cannot detect weeds in your system. The doctor also can’t tell whether you have a smoking habit by looking at your eyes.

Can my doctor tell my employer that I use marijuana?

Doctors are required to keep patient information confidential unless they are being abused or causing harm to others.

+ 2 Sources

EHproject has strict sourcing guidelines and relies on peer-reviewed studies, academic research institutions, and medical associations. We work mostly with peer-reviewed studies to ensure accurate information. We avoid using tertiary references. You can learn more about how we ensure our content is accurate and current by reading our editorial policy.

  1. Turner, A.R. and Agrawal, S. (2022). Marijuana. [online] Nih.gov. Available at: https://www.ncbi.nlm.nih.gov/books/NBK430801/#:~:text=Clinicians%20can%20detect%20marijuana%20use,from%201%20to%2030%20days.
  2. Wong, A., Montebello, M., Norberg, M.M., Rooney, K., Lintzeris, N., Bruno, R., Booth, J.D., Arnold, J.C. and McGregor, I.S. (2013). Exercise increases plasma THC concentrations in regular cannabis users. Drug and Alcohol Dependence, [online] 133(2), pp.763–767. doi:https://doi.org/10.1016/j.drugalcdep.2013.07.031.


A dedicated pediatric nurse with a passion for nutrition and wellness, Teresa has made it her mission to empower families with the tools and knowledge they need to promote optimal health and well-being in their children.… See More