Article written by
Tina MagrabiSenior Content Writer
Content reviewed by
Dr. Lewis JasseyMedical Director - Pediatric Medicine
Table of contents
Cannabis is federally illegal, and there are many jobs that prohibit its use by their employees, even in states with a medical marijuana program.
Although there are protections for medical cannabis patients in some states (for example, off-duty use for medical purposes is fine in states like Arizona or Delaware), there are other states where such protections are not in place.
Our bodies rid themselves of the terpenes, flavonoids, and most cannabinoids in marijuana rather quickly. However, tetrahydrocannabinol (THC) — the psychoactive cannabinoid responsible for cannabis’s high feeling — can be detectable anywhere from one day to over a month after consumption.
The length of time that THC and its metabolites stay in your system depends on a variety of factors, including:
- Body size
- Dose and frequency of use
- Consumption method
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Factors That Influence Retention
Higher doses of cannabis will result in longer THC retention periods. Microdosing is one way to reduce the impact of THC and minimize its retention time.
Frequency of Use
THC is more likely to stay detectable in your system if you use cannabis daily. People who consume marijuana infrequently are less likely to retain THC in their systems for long periods of time.
When you breathe in THC via smoking, vaporizing, and using inhalers, it passes through the lungs and almost immediately takes effect. This usually lasts between one and four hours, depending on how much cannabis has been smoked, vaped, or inhaled.
Small doses of THC are unlikely to last longer than a couple of hours, whereas larger dosages (e.g., consuming a THC concentrate with a dab rig) can last longer — three to four hours or even eight hours if a potent concentrate has been used.
Other delivery methods, such as sublingual tinctures, may last slightly longer than smoking marijuana. Consuming edibles also results in a longer retention time for many people.
As cannabis metabolites are fat-soluble, they bind to fat molecules in the body. This means cannabinoids stay in the body for quite some time, especially for people with high body fat percentages.
For heavy users who ingest cannabis multiple times a day, THC metabolites may be detectable up to 90 days after consumption, usually in hair and urine.
Age, weight, individual metabolism, levels of physical exertion, and genetics also affect how long cannabinoids stay in the system.
THC-heavy strains will naturally result in THC staying in your system longer than CBD-rich strains. Choosing a balanced ratio of 1:1 CBD:THC may help reduce the amount of time that THC stays in your system, but there is no guarantee.
How Long Marijuana is Detectable on Drug Tests
The following are general guidelines for how long marijuana shows on drug tests. Note that there may be slight variances depending on your weight, body fat percentage, and prior cannabis experience, among other factors.
Urine testing is one of the most common ways of testing for cannabis use. Cannabinoid metabolites are detectable in the urine for the following lengths of time after consumption:
- Infrequent users (once a week or less): One to three days.
- Occasional users (three times a week): Three to seven days.
- Moderate users (four times a week): Five to 10 days.
- Daily users (once per day): 10 to 30 days.
- Heavy daily users (multiple times a day): 30-plus days.
The urine marijuana test will give a positive result if the amount of THC in the sample is over 50 nanograms per milliliter (ng/ml). This is called the cut-off level.
Saliva testing is the most common method for roadside testing. For occasional marijuana users, cannabinoids are detectable in saliva between one and three days. For heavy users, it is possible to detect THC metabolites up to one month after the last use.
Hair testing is the most sensitive and can detect THC metabolites up to three months after consumption. Trace amounts of THC metabolites can remain in the hair for a long time. A 1.5-inch hair segment is usually taken to provide a window of use spanning the past three months.
While hair follicle tests can provide information about a person’s cannabis use, they are not always accurate and often produce false negatives. Hair samples are also prone to contamination, making them difficult to rely on with high accuracy. Hair follicle testing is usually used in tandem with urine testing.
THC and its metabolites are detectable immediately after ingestion or inhalation in the bloodstream. For those who have been using large amounts of cannabis regularly, THC metabolites are detectable in blood samples for up to one month after the last use.
Is It Possible to Detect CBD?
Most drug tests searching for cannabis are calibrated to detect THC and its metabolites. While it is certainly possible to test for CBD and other cannabinoid metabolites, it is not common to do so.
CBD may produce a positive result for cannabis use when products with high concentrations of CBD are used regularly. In such instances, it is not the CBD that is being detected but the buildup of trace amounts of THC over time. THC has a tendency to accumulate, even when used in minuscule amounts.
Some hemp-derived CBD products have tested above the permitted 0.3% THC limit, so it is possible to ingest a CBD product that contains higher levels of THC without realizing it (i.e., it produces almost no psychoactive effect but ends up being detected and pushes you past the 50 ng/ml THC metabolite threshold).
Carefully read the labels of all CBD or hemp-derived products to ensure you are aware of what is included before consumption.
How To Get Rid of Marijuana in Your Body Faster
Cannabinoids are lipophilic, meaning they bind with lipids and fats in the body, making it difficult to clear the body of their metabolites. Exercise, a healthy diet, proper hydration, herbal supplements, and vitamins could help rid the body of cannabinoids and their metabolites faster.
Still, it will likely take one to two months to get below the threshold for most regular users.
Regardless of the testing method, cannabinoids can be incredibly difficult — if not impossible — to flush out with over-the-counter products touting their ability to help you beat your upcoming drug test. Time and patience are your greatest allies when attempting to rid your body of cannabis metabolites.
The only way you can guarantee testing below the 50 ng/ml cut-off level for cannabis metabolites is to cease consumption and wait for your body to rid itself of the metabolites naturally.
Consume cannabis legally and responsibly with a medical marijuana card. Leafwell’s qualified healthcare providers can help you apply online for your MMJ card today.
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Originally Published December 2022
Last Updated February 2024
Frequently Asked Questions
How long does cannabis stay in urine?
Cannabis is generally detectable in urine for up to 30 days, although this window could last longer for regular daily users.
Will I fail a drug test if I smoked weed a month ago?
It is possible that you could fail a drug test if you smoked weed a month ago, as marijuana is detectable in blood and urine for up to 30 days. Hair tests are the most likely to reflect if you used marijuana a month ago, as these tests can detect THC for up to three months in some users. However, you may fall below the 50 ng/ml threshold if you don’t consume much.
Does CBD show on drug tests?
Other cannabinoids like CBD are also lipophilic, meaning it is possible to detect them for the same period as THC. However, most standard drug tests do not test for CBD or its metabolites. Instead, they test for THC and its metabolites.
This means that unless you regularly use high amounts of CBD that contain more than the 0.3% limit THC for CBD products, it is unlikely (but still possible) that CBD-only products will result in a positive drug test for cannabis.