There’s a risk that CBD users may fail a drug test. I know you've probably read that drug tests don't test for CBD. That's true, but you might fail a drug test anyway because many CBD products come with THC. There's also a specific drug test used today that can't distinguish CBD from THC.
CBD products just became legal federally, and it's a mess. Employers, law enforcement, and drug testing facilities have failed to differentiate legal CBD products from marijuana. I'm going to dig into all the research that shows what it takes to fail a drug test after using CBD products.
Note: you can scroll to the bottom of this article for a summary of the research.
A standard drug test measures the percentage of THC metabolites—usually THC-COOH—in the urine or blood. THC is the psychoactive compound in cannabis that is responsible for the “high.” Pure CBD does not elicit a high and drug tests aren’t designed to look for it.
Drug tests look for THC and many people boldly claim that “there’s no need to worry about CBD products and drug tests.” That's entirely false forCBD products that contain THC. There’s also a specific drug test that may fail you even though you were using pure CBD, but we'll start with hemp extracts that contain THC.
Marijuana and hemp are both types of cannabis plant. Hemp is defined as containing less than 0.3% THC. Hemp is federally legal because it contain slow amounts of THC. Drug tests look for THC. The question is “can hemp-derivedCBD products contain enough THC to fail a drug test?” The answer is yes.
There are many news reports of people who claim that CBD products caused them to fail a drug test. People have lost jobs, driver’s licenses, child custody, and faced substantial legal problems from failed drug tests. Failed drug tests happen fromCBD products and people are suing CBD companies for giving no fair warning.
It’s a good idea to avoid all CBD oils with THC if you don’t want to fail a drug test that looks for THC. The products that contain THC are usually referred to as “full-spectrum” CBD or hemp extract. A study published in JAMA found that 18 out of 84 CBD products contained THC. However, many of the CBD products that contained high enough levels of THC to risk a failed drug test did NOT list THC on the label.
Testing here, at CBD Examine, has also revealed the presence of THC in many CBD products that claimed “no THC.” We found that some of the products that tested THC positive even came with lab results from the manufacturer that claimed “no THC.”
The bottom line is that CBD oil may come with enough THC to risk a failed drug test even if the product claims “no THC.” That’s one reason we, at CBD Examine, lab test CBD products.
The first thing to know is that lab-test related failures happen about 12 million times per year in the U.S. and most people will receive a medical diagnostic error in their lifetime. You can bet that if mistakes happen in the medical field, mistakes will also occur in the labs that test for drugs. According to research presented on WebMD, “drug tests generally produce false-positive results in 5% to 10% of cases and false negatives in 10% to 15% of cases.” There’s a chance you’ll fail a drug test before you even introduce any questionable substance to your body, including CBD.
The risk of failing a drug test because of CBD is not measurable. There’s no solid research and there are a lot of factors at play. There’s a common myth that you would need to take 1,000mg of CBD oil to fail a drug test, which is an absurd amount of CBD and is not backed by science.
Consumerlab.com states that there is roughly a 10% chance of failing a drug test with CBD oils. However, it’s a really “rough” estimate because the risk significantly changes based on an individual’s metabolism of THC, the CBD product, the THC content, the consumption method, the dose, the length of use, and the drug test performed. Digging into the research of what it takes to fail a drug test will give us a better understanding of the risk and why we can’t accurately predict if an individual will fail a drug test from CBD oil.
I'll first go over what we know about THC drug testing from marijuana research to give you an idea of how THC tests work and why this research can be misleading. After that, we’ll jump into a few studies on hemp and failed drug tests.
Most of the research we have for THC detection comes from marijuana use. Here’s a rough estimation of marijuana use and detection times. You’ll need to take this information with a grain of salt because studies are conflicting and absorption varies among individuals.
The good news is that the single use of marijuana is only detectable for one to three days, which is relatively consistent in research. Researchers classify single use as an entire marijuana cigarette, which they administer to participants. It’s a lot of THC. The marijuana strain and cigarette size are different in every study, with THC doses ranging between 27 mg and 70 mg.
These are significantly higher THC doses than you can get from hemp-derived CBD products. Most of the CBD products that we’ve tested have below 1 mg of THC per dose and many have under 0.30 mg of THC per dose. Lazarus Naturals was one of the most potent products that we tested, which had 2 mg of THC per dose. One study found up to 6.43 mg of THC per mL dose in CBD products, which is rare and unacceptable (Many people will start to feel “high” from doses of THC as low as 2 or 3 mg).
The point is that most people test clean a day or two after consuming 20-70 times the amount of THC found in your typical CBD product. It would be natural to assume that there’s no way that you’ll fail a drug test from CBD products based on “single use” THC research. And for a single use of a CBD product, it's doubtful that you'll test positive after three days. Multiple doses of a CBD product are a different story.
Dr. Norbert Kaminski, professor of pharmacology and toxicology at Michigan State University, points out that THC is fat-soluble and can build up in the body over time. THC is stored in your fat cells. The release of THC is individualized and changes based on everyday activities. For example, researchers from Norway found that a single 45-minute workout nearly doubled THC blood levels in one chronic marijuana user. Small amounts of THC from CBD products may build up over time and later be released into the blood or urine as THC metabolites, which drug tests measure.
THC research is a mess because THC is fat-soluble. This is one reason why chronic marijuana users can fail a drug test for up to 90 days after their last use. On the flip side, some chronic marijuana users can reach non-detectable levels of THC within a week. Meanwhile, a person who only smokes occasionally can have THC in their system for several days or several weeks after their last use. THC is fat-soluble and everyone's metabolism is different.
Take a look at this study from 1985:
Occasional, regular, and chronic marijuana users may pass a test one day and fail the test a few days later. For context, federal drug tests use a cutoff of 50 ng/ml to confirm THC metabolites, while some employer drug tests use 20 ng/ml of THC metabolites. It increases your risk of failing a drug test if your employer is looking for lower levels of THC metabolites (20 ng/ml) in the urine. I would also expect that a lower testing threshold (20 ng/ml) comes with significantly higher error rates or false positives.
The chart above shows that individuals within a group of chronic users will fail or pass drug tests at fluctuating rates. This throws a wrench in all of the THC-detection research. Studies that show a person can pass a drug test in a few days may be limited because that person may fail a few days later. Again, take the research above with a grain of salt because other THC studies have conflicting results due to the varying THC doses and individual THC metabolisms.
The absorption method changes THC detection as well. You may absorb two or three times as much THC from smoke as from an edible since edibles lose THC during the digestion process. However, one study found that a single brownie (20 mg THC) was detectable for up to 12 days after ingestion. Brownies have a low THC absorption rate, yet this study found that edible THC was detectable for up to 12 times longer than the single marijuana cigarette (27 mgTHC) mentioned in the prior study.
So how does this marijuana-THC research compare to the CBD oil that you inhale or absorb orally, sublingually, or topically? It lets us know that THC detection times are wildly different due to the THC dose, absorption method, individual metabolism factors, and the type of drug test performed. Keep that in mind as we look at the limited number of studies on hemp and drug testing.
Researchers from the National Institute on Drug Abuse, Baltimore, found it possible to fail a drug test after consuming low doses of THC. These THC doses are what you might find in a typical CBD product that contains THC or is labeled “full spectrum.”
Seven participants used varying THC doses for five days and had multiple drug tests over a ten-week period. One participant failed a federal drug test (50 ng/ml) with a daily dose of 0.39 mg of THC. Three participants—out of seven—failed a federal drug test (50 ng/ml) with a daily dose of 0.47 mg of THC.
Lowering the drug test cutoff to 20 ng/ml increased the risk of a failed drug test dramatically. Three participants failed a 20 ng/ml drug test at 0.39 mg of THC per day and six of the seven participants failed with 0.47 mg of THC per day.
Multiple drug tests(20 ng/ml) were administered and the risk of a failed drug test was 5.1% for the 0.39 mg THC dose and 12.8% for the 0.47 mg THC dose. Again, many tests were completed over ten weeks and the risk of failing a drug test was low (12.8%) even though six out of seven participants had failed at least one test at the 0.47 mg THC dose range. A total risk of 12.8% sounds great but 85% of participants failed the drug test at some point. An individual’s THC levels fluctuate and drug tests are like rolling a dice.
Many CBD products have a daily dose of 0.47 mg of THC. You’ll find some of the more potent CBD products come with 1 mg or 2 mg in each dose. That’s a total of 2 mg or 4 mg of THC per day if you only dose twice per day. This study suggests that there is a risk that you will fail a drug test with CBD products, albeit low, and that the risk goes up as the THC potency goes up and the drug test cutoff is reduced.
A 2001 study out of Berkley, California, gave participants up to 0.60 mg of THC per day for 40 days. Only 1 out of the 15 participants failed a federal drug test (50 ng/ml). This study has been referenced by a lot by CBD manufacturers who claim that hemp products are unlikely to produce a failed drug test.
This research is challenging to compare to most CBD products. The doses of THC were mixed into large doses of hemp seed oil. Although they consumed a decent amount of THC (0.60 mg), the potency was weaker than a typical CBD oil. Participants consumed 20 mL of hemp oil instead of your average 0.5 mL or 1 mL dose of CBD oil. The dilution of the THC might have played a part in reducing the risk of a failed drug test.
This study was meant to mimic large quantities of hemp seed oil. Hemp seed oil contains only trace amounts of THC. CBD products are derived from the hemp flower, which may contain substantial amounts of CBD and THC. The research here suggests that you probably won’t fail a drug test from hemp seed oil. However, I wouldn’t bet that you’ll pass a drug test from CBD oil based on this popular study that was aimed at hemp seed oil consumption.
A new study found that the single use of your typical CBD product may produce a positive drug test within five days of use.
Researchers administered a vaporized dose of 100 mg of CBD and 3.7 mg of THC to six individuals. Two of the six participants tested positive for THC at the federal requirement (50 ng/ml). The two participants only tested positive once each at the federal level and multiple tests were completed in the five-day duration. I would bet that the failed drug tests came within three days of use, which would be consistent with the vast body of marijuana research.
Nine samples also tested positive at the 20 ng/ml cutoff, but the study did not specify how many of the participants these failed drug tests came from. We don’t know if two people failed this 20 ng/ml drug test or all six failed the drug test. However, the study noted that a lower cutoff increased the risk of a failed drug test.
The researchers also tested pure CBD, which did not produce a failed drug test. “These results suggest that pure CBD, used once by itself, will not cause a positive drug test,” says the author, adding “it does not take much THC exposure to trigger a positive test for some people.”
This study should make us cautious of CBD products and drug tests. Some of the single-use marijuana research used over 100 times the amount of THC used here. This is a much lower level of THC needed to cause a failed drug test than previously reported. Other cannabinoids within the cannabis plant may be adding to the risk of a failed drug test.
I would also caution that this study used vapor, which may come with less risk than other methods of absorption. The single-use brownie study mentioned earlier shows that oral THC may produce detectable THC for up to 12 times longer than smoke or vapor.
This study needs to be updated with the use of sublingual and oral CBD products. Most CBD products come with healthy fats because it increases CBD absorption. Studies have found that healthy fats increase cannabinoid absorption by up to 14 times. You want healthy fats in a CBD product for increased absorption, but it may also increase the risk of a failed drug test. Repeated doses will also increase the risk.
The New York Times recently published an article that referenced a little-known CBD study. It reminds us that we don’t know much about CBD and drug testing. The study found that a common drug test can’t tell the difference between CBD and THC. The test in question uses gas-chromatography mass-spectrometry (GC-MS). The test requires a chemical to be added to identify THC. Trifluoroacetic anhydride (TFAA) is one of those chemicals that is still used today, and it turns CBD into THC. When users of pure CBD take this drug test, specifically with TFAA, they can fail a drug test. It’s important to note that most of the internet claims that it’s impossible to fail a drug test from pure CBD.
CBD is converted into THC in acidic conditions. Researchers previously theorized that you could fail a drug test from pure CBD because the stomach is acidic. It’s still possible that trace amounts of CBD may convert into THC in the stomach, but recent research has found that stomach acid will not affect a drug test. The test using TFAA is a significant risk, however, because it has the perfect acidic condition to convert CBD into THC.
We know that it’s possible to fail a drug test from a single use of 3.7 mg of THC. Consumer CBD products recommended around 5 mg to 160 mg of CBD per day. This specific TFAA test can't tell the difference between CBD and THC. Most CBD users would likely fail the TFAA test because CBD is consumed in much larger doses than THC.
This test is still used today, although hopefully it will be phased out soon. I’m sure there are a lot of lawyers that would love to seek damages for the numerous CBD users that have been screwed over by this test. What other drug tests are ineffective that we don’t know about? Even if you didn’t take this test, one could argue that the absence of CBD research on testing facilities should make failed drug tests for CBD users invalid.
A new study found that common cannabinoids, such as CBD, CBC, and CBG, found in the hemp plant did not cause a failed drug test. The study used one of the most common drug testing methods, which measures immunoassays. However, the researchers found that low doses of CBN did trigger a false positive for marijuana use.
CBN is one of the most common cannabinoids found in both marijuana and hemp. It’s best known for adding to the relaxation effects of THC. This study suggests that the many CBD products that contain CBN come with an additional risk of failing a drug test.
There are over 100 cannabinoids found within the cannabis plant. What other cannabinoids may contribute to a failed drug test? Again, the lack of research should make all drug tests on CBD users questionable.
The risk of failing a drug test from a marijuana or hemp cream is slim to none. Research shows that topical THC does not enter the bloodstream, and you will not fail a drug test from topical THC. I also could not find a single report or study to suggest that anyone has failed a drug test from any topical cannabis products.
Animal research shows that topical CBD is effective at reducing inflammation in arthritic rodents. Topical CBD absorbs into the skin ten times better than topical THC. CBD is highly effective at treating specific areas of the body, but research shows only limited amounts of topical CBD pass into the blood. It’s unlikely that the small amounts of CBD from topical use would create significant CBD blood levels in humans. I'm not sure if topical CBD could even generate enough CBD in the blood to cause a failed drug test with the specific TFAA drug test mentioned prior that can’t tell the difference between CBD and THC.
Given the current research on topical THC and zero reports of failed drug tests from topical cannabis products, I would say that the chance of failing is close to zero. However, we need more research to say with 100% certainty that it is impossible to fail a drug test from topical CBD or topical cannabis products.
In 2019, a grandmother was arrested at Disney World for carrying a bottle of pure CBD oil. She used the CBD for her arthritis. Grandma was sent to jail on felony charges of possession of hashish or THC extract. I know the bottle was pure CBD because I sent the same product to a local lab and it contained zero THC. The cheap field test that the arresting officers used couldn't distinguish CBD from THC.
For context, this is part of a much larger problem that regularly sends innocent people to jail. You may remember in 2015 that a Krispy Kreme customer was arrested for possession of meth. That’s right, a field test used by officers mistook the glaze of Krispy Kreme doughnuts for meth. He won a small settlement but his arrest record and internet presence are now paired with meth. Data from the Florida Department of Law Enforcement Lab shows that over 20% of positive field test results come back as negative when tested with more sophisticated lab equipment. The best news comes out of Florida, doesn’t it?
These cheap $2 field tests use junk science and the results may be even worse for CBD.
Multiple police departments and news agencies are reporting that standard field test kits can't tell the difference between CBD and THC. What's more, many government labs don't have the equipment to test for hemp products. A Virginia judge recently tossed out a marijuana case because their government-run labs were not capable of testing for accurate levels of THC.
There is a small risk that you’ll be arrested for carrying a CBD product in a state where marijuana is illegal. However, it would be a false arrest based on junk science. I would assume that this risk will go down exponentially as police departments are sued for false arrests on CBD consumers.