Fraser Horton
Fraser Horton
Last Updated on October 10, 2021

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 half-life of THC 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.

All of these elements combined 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. 

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.


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