How Long Does Marijuana Stay in Your System?

Part of the complete guide to understanding addiction

Table of Contents
  1. How long does Marijuana stay in your system?
  2. What are THC and CBD?
  3. How does your system process Marijuana?
  4. How quickly does marijuana start working?
  5. What factors affect how long weed stays in your system?
    1. Frequency of use
    2. Urine Test
    3. Blood Test
    4. Saliva Test
    5. Hair Test
    6. Marijuana in Your System Chart
  6. Understanding THC and The Body
  7. Getting Treatment for Marijuana Addiction

How Long Does Marijuana Stay in Your System?

Unlike many other drugs, marijuana can stay within your system for long periods of time. This can cause difficulties when you need to pass a drug test, whether you are part of a sports team, an employee, or part of other organizations that test and enforce substance abuse policies.

The length of time that marijuana stays in a person’s system depends on how much body fat they have, the dose they smoke or consume, and how often they use marijuana. For different reasons, you may wonder how long marijuana can stay in your system, how it is processed, and how long you can count on the effects to last.

Although the variety of factors make it difficult to predict exactly how long marijuana will stay in your system, this article will help you estimate what you can expect.

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What are THC and CBD?

Each time a person uses cannabis, whether through smoking or ingesting, THC and many other chemicals enter the system. The most important compound in marijuana is THC, which causes the “high” related to marijuana. THC is short for tetrahydrocannabinol, and although many other plants contain it, it is mostly connected with marijuana.

Many often confuse THC with CBD, and although similar, they have quite a few differences. They both have a similar composition and contain 21 carbon particles, 30 hydrogen particles, and two oxygen particles. However THC and CBD are organized completely differently. The difference in their chemical structures changes how they affect your body when you smoke or ingest a drug containing them.

Both CBD and THC work with the receptors that discharge neurotransmitters in a person’s head, leading them to influence things like mood and memory. The main difference between them is that THC causes a “high,” but CBD does not.

Instead, CBD helps with other areas of the body and can promote physical health. It is often used in over-the-counter drugs and medications and contains no THC. It is derived from the hemp plant, which is related to the marijuana plant, and can be beneficial in its use.

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How does your system process Marijuana?

When someone first ingests or smokes marijuana, the THC and other chemicals enter the body. From there, they begin their path traveling through the brain, the bloodstream, and then to the rest of the body.

If the marijuana is being smoked, then it goes directly into the lungs and is absorbed within seconds. This is because our lungs are fixed with many alveoli, which are the minuscule air sacs where gas exchange happens. These alveoli have a very large surface area, making it simple for THC and different substances to enter the body. THC is also used in vapes as an alternative to smoking as it does not burn the cannabis. Vaped marijuana and smoked marijuana enter the body in the same manner.

Ingesting marijuana however, delivers the THC straight to the blood rather than traveling through the lungs.

However the substance is administered it binds to the receptors and blocks the neurotransmitters, causing the feeling of a euphoric high. These are the usual effects experienced when marijuana is smoked or consumed, but some people may experience different effects.

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How quickly does marijuana start working?

Once marijuana enters the system, it can take between 2 to 10 minutes to feel the effects when the marijuana is smoked, and 30 to 60 minutes when ingested. In some instances it can even take as long as 3 hours.

When smoked, the effects of cannabis peak after about 10 minutes, but the effects can remain for the next 1 to 3 hours. Occasionally, they may still linger even 8 hours after usage. When marijuana is ingested, the effects peak after about 2 hours, and may remain for about 24 hours in total.

The time that the effects last changes from person to person, and they depend on the THC levels within the body. It also depends on how much you consume, your body weight and fat percentage, your metabolism, whether you ate beforehand, and your personal tolerance.

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What factors affect how long weed stays in your system?

Marijuana can linger in the body long after the actual effects wear off. Multiple factors affect how long weed will stay in the body and be detectable on a drug test. Frequency of use and the type of test being administered are the most important factors to consider, but there are other things to keep in mind. Body fat, dose taken, and sensitivity of the test all need to be taken into consideration as well.

Frequency of use

Frequent users are more likely to fail drug tests than infrequent users. This is because in a daily user, THC can stay in their system for up to 90 days after their last use in a hair test. Drug tests can detect even small amounts of THC in the system, so it is important to understand which test can detect different levels of THC.

Someone who uses marijuana one time can expect it to stay in their system for 3 days, and someone who uses it 2 to 4 times a week, or an occasional user, can expect it to stay in their system for 5 to 7 days. If they use marijuana 5 to 6 times a week, it can stay in their system for 33 to 48 days. Even with these estimates, there are always uncommon cases where THC can be detected after even longer periods.

Urine Test

Urine testing is the most common form of drug testing because it’s simple, quick, and painless. With this method of testing, THC can be detected in occasional users 3 days after the last use. In moderate users, it can be detected 5 to 7 days after use. In daily users, it can be detected 30 days or more after their last use. Often, THC can be detected even further ahead.

Blood Test

A blood test is a far less common drug testing method, as it can only gather results from the past few hours. THC is detectable in the blood just seconds after it is inhaled

Saliva Test

A saliva test can be conducted when the person has inhaled marijuana smoke or has been exposed to it. Often, it is used by police forces in roadside testing. A saliva test, THC, can be detected for 1 to 2 days for occasional users and 2 to 3 days for chronic users after their last use.

Hair Test

A hair test is the least common drug testing method, and they are a little more complicated than the urine, blood, and saliva tests. Small blood vessels allow the weed to reach the hair follicles, and THC can be detected 90 days after usage.

Marijuana in Your System Chart

One time2 -4 Times
per Month
2 – 4 Times
per Week
5 – 6 Times
per Week
Urine Test3 Days3 Days5 – 7 Days30+ Days
Blood Test3 – 4 Hours3 – 4 Hours3 – 4 Hours3 – 4 Hours
Saliva Test1 – 2 Days1 – 2 Days2 – 3 Days2 – 3 Days
Hair Test90 Days90 Days90 Days90 Days

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Understanding THC and the body

The amount of time that marijuana stays in your system depends on several factors, such as frequency of usage, the sensitivity of the test, and the dosage of THC. Frequent users of marijuana are more likely to fail their drug tests because of the length of time that the THC remains in their system after their last use.

Because of this, it is important to understand how THC affects your system and how you can control your usage of marijuana.

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Getting Treatment for Marijuana Addiction

Marijuana is a very addictive substance that can lead to very detrimental effects on your life. There are treatment options available that can help you get your life back. Our admissions counselors are standing by to help you, reach out today!
For information on half-life of other drugs, including how long fentanyl stays in your urine and how long meth stays in your saliva, read our online resources.


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