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.
Drug tests look for THC
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 for
CBD 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.
Many CBD oils 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 contains
low amounts of THC. Drug tests look for THC. The question is “can hemp-derived
CBD 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 from
CBD 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
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.
What’s the risk of failing a drug test from CBD?
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 1,000
mg 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.
How much THC causes a failed drug test?
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.
What we know from marijuana research
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.
- Single use of one marijuana cigarette: 1-3 days
- Occasional or regular use: 3-30 days
- Chronic use: 5-90 days
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
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.
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 mg
THC) 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.
Hemp Products and Failed Drug Tests
CBD products and failed drug tests
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.
Hemp seed oil and drug tests
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.
Single-use CBD products and failed drug tests
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.
Pure CBD and a failed drug test
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.
CBN and a failed drug test
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.
Topical CBD and failed drug tests
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
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.
Law enforcement and failed drug tests
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.
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.
Sum it up
- Drug tests produce false positives in 5-10% of
cases. Lab testing comes with well-documented error rates and many people who
don’t use drugs fail drug tests.
- Consumerlab.com states that there is roughly a 10%
chance of failing a drug test with CBD oils. However, there are a lot of
variables that affect failure rates.
- No one can accurately predict if you will pass a
drug test while using CBD products. The risk significantly changes based on an
individual’s metabolism of THC, the CBD product used, THC content, the
consumption method, the dose, the length of use, and the drug test performed.
- THC research shows that some people may pass a
drug test within a few days of their last use, while others can take up to 90
days. Multiple uses increase THC detection times. However, the uniqueness of
each individual’s THC metabolism plays the most significant factor in THC
detection times, which makes drug-test research conflicting and often
- Drug tests look for THC, not CBD. However, many
CBD oils contain THC and companies are not honest about their THC quantities.
- A specific drug test (GC-MS with TFAA) can’t
tell the difference between CBD and THC. The test is still in use today and may
cause a failed drug test for pure CBD consumers.
- One study found that three out of seven
participants failed a drug test (at 50 ng/ml) with a daily dose of 0.47 mg of
THC, which is a lower THC dose than many CBD products contain. The risk of a
failed drug test went up for drug tests that look for smaller quantities of THC
(20 ng/ml) in the urine.
- A new study found that two out of six
participants failed a drug test from a single vaporized dose of 100 mg of CBD
and 3.7 mg of THC. This new study suggests that it takes significantly lower
doses of THC to fail a drug test than previously thought.
- Other cannabinoids found in the hemp plant, such
as CBN, may also cause a failed drug test.
- Many drug test field kits used by law
enforcement can’t tell the difference between CBD and THC. False arrests for
marijuana have been made by officers that can’t identify CBD products in states
where marijuana is illegal.
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