
If you are concerned about the amount of time it takes your body to eliminate weed, you’ve come to the right place. Perhaps your employer has announced you will be subject to random drug testing. This is likely to cause much anxiety, particularly if you are a long-term weed user. In this post, we outline roughly how long weed remains in your body.
We say ‘roughly’ because the amount of time it takes your body to flush out all weed toxins depends on many different factors. Despite these factors, we nevertheless attempt to give you a rough estimation of how long it will take your body to flush out all of the weed you have consumed in the past.
We hope this post will serve as a warning to those of you who use weed regularly. Unfortunately, weed does remain in your system for an extended period of time, and the only true way to pass weed drug testing is to avoid this drug entirely.
Where can I buy a cannabis detox kit?
You can buy an effective 4-day cannabis detox kit here
So how long does weed remain in your system?
For the vast majority of regular weed users, weed will remain detectable in the blood for around five weeks after weed was last consumed. If you are an irregular user of weed, the drug may not be detectable in your blood in as little as 10 days following consumption, although there is no guarantee this will be the case.
Naturally, the amount of time it takes the body to eliminate all weed toxins and by-products depends on how long you have been a weed user for. Furthermore, some drug tests will be able to detect weed in your system even when you have not touched the drug for several months.
Specific testing methods
Below, we discuss various means of testing for weed consumption. This includes a urine, blood, hair and saliva test.
#1. Urine testing for weed
By far the most common form of weed testing is the humble urine test. This is also known as urinalysis. If you have smoked weed as a one-off, weed will, fortunately, remain in the urine for around seven days. However, if you are a regular weed user, expect your urine to show a positive result for a period up to around three months following a period of total abstinence.
A urine test attempts to detect THC-COOH. This is a non-psychoactive by-product of weed consumption.
#2. Blood testing for weed
Surprisingly, weed is filtered from the blood far quicker when compared to the urine. For this reason, drug testing companies tend to not favour blood testing in order to detect weed use. Blood testing may detect weed for around 2-7 days for regular users. For the occasional weed user, blood testing is only effective if conducted within 24 hours following the consumption of weed.
Unlike urine testing which attempts to detect the weed by-product THC-COOH, a blood test attempts to detect THC itself. THC is the active psychoactive substance found in weed. This means blood tests are capable of testing for actual impairment due to weed consumption. For instance, if an employee is suspected of smoking weed ‘on the job’, a blood test would categorically prove or disprove whether this was the case, whilst a urine test would not.
#3. Hair follicle testing for weed
Hair follicle testing is highly effective at detecting weed use for heavy users. Hair follicle testing is almost useless when trying to detect moderate weed consumption. For regular weed users, a hair follicle test may detect weed consumption for many months following a period of abstinence.
Hair follicle testing requires expensive equipment and it is a relatively expensive procedure to undertake. Therefore, many employers and organisations tend to favour urine testing when attempting to detect weed use amongst their workforce.
#4. Saliva testing for weed
Saliva testing is an ineffective means of testing for weed use.
Variations in detection times
The above is not intended to be taken as gospel. The actual amount of time it takes your body to rid itself of weed and weed by-products will depend upon many factors. For instance, heavy users will take far longer than casual users to metabolise all weed residue from their system.
Other variables affecting how long weed remains in your system include:
#1. Body fat content
Chemicals contained within weed are collectively known as cannabinoids. When these substances are metabolised, they are stored in fat cells. If your body contains a high amount of body fat, you will retain detectable cannabinoids for longer periods when compared to leaner individuals.
Generally, the higher your Body Mass Index (BMI), the longer weed will remain in your system.
#2. Exercise
Taking regular exercise neither increases nor decreases the amount of time it takes your body to eliminate weed from your system. However, regular exercise does increase the likelihood of your weed test turning out a positive result.
Why? Because when you take regular exercise, your body will burn up excess fat for energy. During this process, cannabinoids stored in these fat cells are released into the bloodstream, thus increasing the odds of your blood or urine test revealing past weed use.
However, if the test is not scheduled for several weeks, regular exercise will help you to burn up cannabinoids, thus helping you avoid a positive test result.
#3. Hydration
If you dehydrate yourself before a test, you are more likely to reveal positive testing? Why? Because when you dehydrate yourself, there will be less water in your blood or urine. This means cannabinoids will be more concentrated in your blood or urine, making it easier to detect their presence.
#4. THC content of the weed you consume
When you consume stronger forms of weed such as skunk, you will build up ever greater qualities of cannabinoids in your system. This will mean it takes the body more time to eliminate these by-products from your system.
#5. Metabolism
The last variable affecting the amount of time it takes your body to rid weed from your system is your metabolism. Metabolism is related to fat storage. If you have a slow metabolism, weed by-products will remain in your system to somebody who has a faster metabolism.
The myth of cheating a drug test
Many people attempt to cheat their drug test by losing weight, drinking water or exercising before the test. This is highly inadvisable, given it’s highly likely your attempts to cheat the drug test will fail. The only guaranteed way to pass the drug test is to stop using weed.
If you are addicted to weed, by far the best way to give up is to go to a residential rehab clinic. To discover your various treatment options, contact ADT Healthcare today on 0800 138 0722.
How long does weed stay in your system infographic
We now outline the above facts and information in graphic format:
About the author:


Jon writes for ADT Healthcare and a number of other websites. Jon graduated with a degree in psychology in 1992. Jon has been in recovery for 19 years.