This is a common question among CBD users who are not also marijuana users. It’s important to consider as the answer could mean the difference between keeping or losing a job, or even possibly being charged with a DUI violation. And it’s fair to ask considering CBD comes from cannabis, and marijuana is a type of cannabis.

This question also raises other questions, such as: Do drug tests test for the presence of CBD? Is there THC in CBD oil? How much THC would it take to trigger a positive result (meaning you test positive for THC)? And, can CBD cause a false positive on a THC drug test?

Today, drug testing is a common practice among U.S. employers hoping to increase productivity and reduce employee absence due to illness. In fact, the U.S. government requires drug testing of all employees. And, of course, one of the drugs for which employees are tested is marijuana.

While drug testing has been on the rise for some time, the number of companies that test for THC is actually falling. The reason for this is that as of writing the U.S. job market has become highly competitive, and many employers can’t afford to rule out employees who test positive for THC—especially in states where medical marijuana use is legal. More and more employers are coming around the idea that the use of cannabis can provide legitimate health benefits.

(In fact, CBD may actually help employees become better focused, more alert, and healthier overall resulting in fewer days missed due to illness and greater productivity. But that’s a topic for another day.)

Refraining from marijuana use in order to keep your job doesn’t do you any good if you’re fired for testing positive for marijuana use as a result of using CBD.

Another major issue of contention has arisen in states with legal cannabis is how to accurately test drivers who are suspected of driving under the influence of marijuana to determine their actual level of impairment.

So, let’s take a look at how drug tests work, and whether or not CBD use is likely to trigger a false positive.

What do drug tests actually test for?

There are a number of illicit drugs for which employers and law enforcement agencies commonly test. These include cocaine, heroin and, of course, marijuana. Each illicit substance has its own method of detection. Here we are only concerned with the detection of marijuana use.

Marijuana use is easily detectable by a number of methods including urinalysis, hair analysis, and saliva tests. What these tests are all looking for, as we mentioned, is previous use of a compound called THC, which is short for delta-9 tetrahydrocannabinol. The metabolites of THC can remain in a user’s system for many days, even weeks.

What’s the difference between THC and CBD?

THC and CBD are very similar compounds. They belong to a family of compounds which are produced by cannabis called cannabinoids.

(Technically, cannabinoids found in plants are called phytocannabinoids, and those produced naturally by our bodies are called endocannabinoids.)

Like THC, research results suggest that CBD offers a wide range of health benefits.

There are only slight differences in these molecules, but that slight difference makes a big difference in how the body reacts to each molecule.

Neurons (brain cells) in the human brain are outfitted with receptors that respond to a wide range of signaling molecules such as hormones and cannabinoids. A particular receptor called the CB-1 receptor has an affinity for THC. When THC binds with the CB-1 receptor it alters the way your neurons behave and causes an altered state of consciousness.

Interestingly, CBD does not bind with CB-1 receptors, but actually blocks them, reducing your susceptibility to THC effects. In fact, supplementation with CBD has been shown to reduce the recovery time from THC effects.

So, as you can see, it would be meaningless for drug tests to test for CBD.

How does marijuana/THC drug testing work?

There are a number of methods that test for THC use. The most common test used by employers is urinalysis—or testing for traces of THC metabolites in urine.

There are also THC use tests which use saliva and hair follicles. Saliva tests are more common for DUI testing since there are obvious challenges with obtaining a urine sample at the scene of possible DUI.

Urine Testing

The vast majority of employers that test for drug use are using urinalysis.

THC’s primary metabolite THC-COOH is fat soluble. That means it may be detectable in urine for up to three weeks after last use depending on how frequently you use it.

THC use can be detected for up to 2–5 days after exposure for infrequent users, while for frequent users it can stick around for as much as two weeks, and for those who smoke marijuana daily, it can be as high as 30 days.

On a side note, urinalysis does not actually detect the presence of illicit drugs. It can only identify the presence of drug metabolites, and therefore cannot be used to determine levels of intoxication.

Hair testing

Marijuana use is also detectable with hair follicle tests. This test can provide a detection period of up to 90 days. (If an individual’s hair is shorter than 1.5 inches, this detection period will be shorter.) Hair drug testing measures THC metabolites embedded inside the hair shaft. Occasional marijuana use may go undetected in a hair follicle test.

Saliva testing

Saliva testing detects the presence of THC itself rather than its inactive metabolites. Because only tiny amounts of the drug are secreted into saliva, THC is extremely difficult to identify in oral fluids. For this reason, most saliva tests typically only detect the presence of THC one to two hours following use. This can be useful in cases of suspected DUI. It cannot, however, be used to determine actual levels of impairment.

Blood Tests

THC is detectable in blood for 12–24 hours for infrequent users and as much as seven days with heavy use. Because blood tests are invasive and difficult to administer, they are used less frequently, and typically only in criminal investigations such as DUIs.

Can CBD trigger a false positive on a drug test?

As we pointed out above, drug tests are designed to look for traces of THC. They are not designed to detect CBD. Thankfully, cannabinoids which are non-intoxicating, such as CBD, will not trigger a positive result on a THC test. However, that doesn’t mean you’re in the clear.

Unless purified, CBD oil products sourced from marijuana are likely to contain some amount of THC. CBD oil products which are sourced from hemp can also contain THC but in extremely small amounts. The legal limit for THC levels in agricultural hemp is less than three parts in 1,000, or 0.3%. So for every 1,000 mg of CBD there is less than 0.3 mg of THC.

What this means is that if you’re taking very large doses of a CBD oil product (1,000 mg/day or more) which contains even tiny amounts of THC, you may be susceptible to a false positive result during an initial urinary screening.

However, a dose of 0.5mg of THC—the amount you might find in a daily serving of hemp-extracted CBD oil—produces a false positive rate of less than 1 in 500.

Is there THC in your CBD?

As mentioned above, some CBD oils out there do include tiny amounts of THC. It’s important for those who are undergoing drug screenings to be fully aware of the contents of their CBD oil. There are a few rules you can follow to avoid false positives due to THC in your CBD oil.

First, don’t use CBD oil made from marijuana. No matter what anyone tells you, you have no way of knowing that the product is THC-free unless you have a lab at home. Don’t use any CBD product that does not actually specify that it was sourced from agricultural or industrial hemp.

Most CBD oil brands will tell you exactly how their product is sourced. Some may even provide lab tests which show the exact percentage of THC in the product.

Some CBD oil products are made with a purified form of CBD called CBD isolate. This CBD has gone through a distillation process which removes all other compounds, leaving behind a product that is over 99% pure CBD. These products are generally better suited for consuming high doses of CBD. Using these products reduce the chance of a false positive due to detection of THC to near zero.

Conclusion

In conclusion, drug tests do not test for CBD. CBD cannot produce a false positive for THC use. CBD which contains small amounts of THC, on the other hand, when taken in large doses might potentially cause a false positive, but even the chances of that are small.

If your livelihood depends on passing a drug test, then you should be using CBD sourced from hemp for normal daily dosages. And if you’re taking large doses of CBD, use a product which contains CBD isolate.

If you are taking high doses of full-spectrum CBD oil and you’re deeply concerned that you might trigger a false positive, it’s a good idea to test yourself using a home test kit so that you can have some peace of mind.