Medically Reviewed by
Jason Crawford

Article Last Updated on January 6, 2023

Marijuana use being federally decriminalized means that many more people are enjoying the cannabis plant in its many forms. Recreational users enjoy the high whenever they want to steal a moment of relaxation, while medical marijuana users are benefiting from its medicinal properties.

Unfortunately, despite all this and the now-changed legal status of weed, mandatory drug testing in the workplace has also increased. Many employers still want to test their employees or job applicants for substance abuse. 

Typical drug tests are designed to look for the presence of specific drugs, like methamphetamines, cocaine, opiates, phencyclidine, and marijuana. This can put marijuana users under strain and they may risk losing their jobs unless they learn how to avoid testing positive.

Each type of drug test has its own cutoff levels, meaning a level at which the concentration of a substance is high enough to be detected. To know how to pass a drug test is to know what amount of THC in your body will be detected.

In this article, we’ll talk about the different types of drug tests and what cutoff levels they have so you know how to better prepare for an upcoming drug screen without being stressed over getting positive drug test results.

How Your Body Metabolizes THC

How your body metabolizes cannabinoids largely depends on your method of consumption. Smoking is the most popular method, with ingestion right behind it. 

Generally, when you smoke or vape marijuana, THC ( delta9-tetrahydrocannabinol) enters your bloodstream directly through your lungs and into the brain. When you ingest edibles, though, it takes longer. Edibles first need to go through your digestive system, after which they are absorbed and partially metabolized by the liver, and only then do they finally enter the bloodstream and into the brain.

When your body metabolizes THC, it breaks it down into smaller byproducts called metabolites. These byproducts bind to the fat cells in the body as THC, and all cannabinoids, including CBD (cannabidiol), are fat-soluble. This is why it takes a while to completely detoxify from weed – your body needs time to get rid of it.

The most well-known THC metabolite is THCCOOH and this is what common drug tests look for as it remains in the body for longer periods of time.

What Are the Different Types of Drug Testing and Their Cutoff Levels?

There are four main types of drug tests and they each have different cutoff levels, as well as detection times.

  1. Urine drug test – the most commonly used drug test in workplaces because it’s non-invasive, fast, and accurate, but what is a high THC level in urine? Well, urine drug tests detect THC metabolites in the urine sample at a concentration of 50 ng/ml (nanograms per milliliter), meaning that if the THC content in your urine is at a level at or above this threshold, then it will cause a positive test result. Urine tests can detect THC in the body 36-72 hours after last use for occasional users, while for heavy users the detection period will be longer.
  1. Blood test – rarely used in the workplace because THC is more quickly eliminated from the bloodstream, and therefore it won’t be effective in this setting. Blood tests are usually used to reveal current impairment, like in DUIs. THC is detectable in blood for about 5 hours, depending on the concentration, and the cutoff level of blood tests is 1, 2, or 5 ng/ml.
  1. Saliva – not common, and the cutoff levels aren’t established. However, THC can remain detectable in saliva for up to 72 hours, or longer with heavy use.
  1. Hair strand test – by far the most accurate, but also used in exceptional situations and when long-term use of marijuana needs to be confirmed. Hair strand drug tests also don’t have established cutoff levels, but they can detect THC metabolites going back as far as 90 days.

THC Half-Life and Other Factors That Can Influence the Test Results and the Presence of THC

Once the body starts degrading THC, its concentration slowly starts dropping, but it does take time. One of the main factors that influence the concentration of THC metabolites is the half-life of THC, which is the amount of time that it takes for one half of THC to be eliminated.

The THC half-life largely depends on factors like:

  • Frequency of use – chronic users will have accumulated THC metabolites, resulting in an overall higher concentration of THC, and subsequently the amount of time needed for the body to eliminate it;
  • Which strain you use – of course, strains with higher levels of THC (typically, Sativas and some hybrids) will cause a larger buildup of byproducts, making it harder for your body to eliminate them in a short span of time;
  • Individual sensitivity – some people are more sensitive to the effects of THC and will generally need less to get high. This also means that they will have a much lower amount of THC metabolites in their body, and it will take them less time to detox;
  • Body fat – each person’s metabolism is different, but it’s thought that people with a higher body fat content will store THC byproducts for longer periods of time than people with lower body fat percentage because THC is fat-soluble and will linger in the fat cells.
  • Test sensitivity – different tests have different sensitivity levels, so a positive test result may also depend on this parameter. 
  • THC dose how much THC you’ve consumed can also affect whether you pass a drug test or not. Since the effects of THC in the body are cumulative, the higher the doses, the bigger the chances of getting a positive test result. This goes hand-in-hand with the previously mentioned factor, frequency of use. So, if you consume weed regularly and in high doses, you’re more likely to get a positive result compared to a person who has only gotten one hit of weed at a social gathering.
  • Sex since females have more body fat than males, this means that females may need more time to metabolize marijuana metabolites. 
  • Hydration –  a person whose body is dehydrated is more likely to get a positive drug test result compared to a person who’s adequately hydrated since dehydration increases the concentration of THC in the body.
  • Exercise – even though exercise may not increase the rate at which your body metabolizes THC, it can increase the percentage of THC metabolites if you exercise right before your test. This happens because exercise causes fat cells to release the THC, and with that, increasing the chances of you getting a positive drug test result.
  • Metabolism – people with a faster metabolism get rid of toxins faster, which means they’re more likely to eliminate THC metabolites more quickly compared to people with slower metabolisms.

All the above factors will influence how your body will process THC and how long it will take for your system to get rid of it or to lower its concentration just enough to make it undetectable. 

Does CBD Show Up on a Drug Test?

Because CBD doesn’t cause intoxicating effects and it’s already legalized in the US, drug tests don’t screen for it. However, if you’re a person who’s consuming CBD, you may get a positive drug test as a result of consuming a product with improper labeling, or a product that has been contaminated with THC.

If you want to minimize the chances of getting a positive test from consuming CBD products, opt for products that contain pure CBD, also known as CBD isolate. These products are 99% pure extract and the production process removes all traces of THC and other plant compounds.

Other CBD products are made from full-spectrum extract which contains 0.3% THC or less, and consuming these products may result in a positive drug test, but only if there’s more THC than it’s allowed. 

Can CBD Products Contain THC?

As we’ve mentioned above, a lot of CBD products contain trace amounts of delta-9-tetrahydrocannabinol (THC), marijuana’s main active ingredient, and if more than 0.3% of THC is present, you risk getting a positive drug test. This generally depends on the quality and composition of the product as well as the sensitivity of the test.

Why Else Might CBD Use Result in a Positive Test Result for THC?

Common reasons why CBD use can lead to a positive drug test result include:

  • Cross-contamination;
  • Secondhand exposure to THC;
  • Product mislabeling.


During the manufacturing process, it’s possible that a CBD product is cross-contaminated with trace amounts of THC. This is more likely a case for companies that make products that only contain THC or CBD. The same applies to cross-contamination at a dispensary, or even at home. For that reason, it’s best to keep your THC products completely separated from your CBD products.

Secondhand Exposure to THC

Even though passive exposure to secondhand cannabis smoke isn’t likely to get you a positive test result, it’s always best to be on the safe side and ventilate the room where weed is smoked. For more information, check out our article on the subject.

Product Mislabeling

Because CBD products aren’t regulated very regularly as the market is still in its infancy and new companies pop up each year, there typically isn’t a third-party lab that tests the composition. If you want to be on the safe side, make sure you check the website to see if the product has been tested by a third-party lab.

Can CBD Turn Into THC in the Body?

In rare cases, CBD can be transformed to delta9-tetrahydrocannabinol (THC) and other cannabinoids. According to a 2017 study by the CIS Clinical Investigation Support GmbH, the Nova-Institut GmbH, and the Department of Neuroscience and Behavior at the University of São Paulo, CBD can transform to THC under acidic conditions.

The experimental conversion in simulated gastric fluid (SGF) is found in in vitro conditions, but does not replicate in in vivo conditions. However, this research is in its infancy and we expect to have more research on the subject in the future.

How Can You Make Sure That a CBD Product Doesn’t Contain THC?

As we’ve mentioned above, your safest bet would be to go for either CBD isolate or broad-spectrum products. The CBD isolate will only contain CBD and won’t contain any other cannabinoids besides CBD. The broad-spectrum products also don’t contain THC, but contain other essential cannabinoids and cannabis compounds such as terpenes and flavonoids.

Will CBD Oil Make You Fail a Drug Screening Test?

There is a common concern about using CBD products and drug testing. CBD oils, tinctures, and edibles (gummies, chocolates, candies, etc.) are the most popular products and many people use them to treat various ailments. However, many CBD users also wonder if these products may cause a positive result on a drug use screening.

To answer this question, we have to look at the different types of CBD products.

  • Products that contain CBD isolate are pure CBD products. This means that there are no other cannabinoids or terpenes present, including THC;
  • Broad-spectrum CBD products contain CBD and other cannabinoids, but they are THC-free;
  • Full-spectrum CBD products contain all the cannabinoids and terpenes found in the hemp plant, including THC.

It’s important to note that the hemp plant only contains trace amounts of THC, or 0.3 percent THC. Normally, this is not enough to get you high, and it shouldn’t result in a positive drug test unless you use large amounts.

However, not all manufacturers are transparent about their full-spectrum CBD oils, meaning not every product labeling is accurate. This is partly because CBD oil has not yet been approved by the US Food and Drug Administration (FDA) as a dietary supplement, and the regulations aren’t clearly defined for all manufacturers.

Therefore, some full-spectrum CBD oils may have enough THC (more than the intended 0.3%) to result in a failed drug test. Legitimate manufacturers test their products at third-party labs before they put them for sale, and they will usually have their results up on their website for easy access (or somewhere on the packaging).

Can You Get a False Positive?

If you’re wondering whether CBD shows on drug tests and if it can cause a false positive result, you’re not alone. False-positive drug test results are not impossible, but they are extremely rare. Generally, they can happen if the test has lower cutoff levels which increase the chances of an incorrect reading, but they can also happen if the test is not specifically designed to detect THC.

If you happen to get a false positive, you can ask your doctor to order for your sample to get tested using the gas-chromatography mass-spectrometry (GC-MS) method, given that this is a much more precise and accurate method.

Finally, there are home-testing kits that you can take to check your THC levels prior to your scheduled drug test just to see where you’re at.

A passionate advocate for the benefits of cannabis. Fraser Horton, who has a background in botany and a strong love of nature, has spent years researching how cannabis affects the body and mind. He established Leaf Nation in 2020, where he has devoted himself to educating people about the legalisation of marijuana and its safe and responsible use. Fraser is committed to highlighting cannabis’ potential for improving wellness and working to dispel the stigma associated with its use.


The information presented on this page is provided as a public service to aid in education and is derived from sources believed to be reliable. Readers are responsible for making their own assessment of the topics discussed here. In no event shall Leaf Nation be held reliable for any injury, loss or damage that could happen if using or abusing drugs.