Very small amounts of THC present in the material that CBD is extracted from can get into the CBD oil in high enough amounts to result in a positive drug test. This scenario may be more apt to occur when CBD oil is purchased from cannabis dispensaries in places where cannabis is legal, as opposed to an online retailer.
There are many distinctions between marijuana and hemp that relate to CBD oil. Marijuana contains both THC (the psychoactive component) and CBD, whereas hemp contains CBD and only trace amounts of THC. Hemp contains many cannabinoids—CBD is only one example.
While some CBD oils claim to be isolates, they may be full spectrum oils and actually contain more cannabinoids (such as THC) than they claim.
3. Mislabeling of Products
Inadvertent exposure to marijuana (via secondhand smoke) is unlikely to be enough for a person to get a positive drug test result, but it is possible. Being in a room with heavy pot smokers for several hours may cause the inhalation of enough THC containing smoke to result in a positive test.
There are several common reasons a person fails a CBD drug test.
The conclusion is that it’s still theoretically possible for traces of THC metabolites to be present in the stomach acid in the instance where “less-purified CBD productions” are ingested.
Arno Kroner, DAOM, LAc, is a board-certified acupuncturist, as well as an herbalist and integrative medicine doctor. He operates a private practice in Santa Monica, California.
Despite the widespread use of urine drug tests, there appears to be some inconsistency in the interpretation of test results. Considering the significant consequences a false-positive result can have (such as loss of job or imprisonment), this is somewhat surprising. But it is also something to be aware of, because it may mean that what is considered a pass (a negative result) in some circumstances may be considered a fail (a positive result) in others.
It is difficult to say how much THC needs to be present to cause a positive drug test because this depends on several drug and patient-specific variables, and also the cutoff value for the test.
Several patient factors can also affect the result, such as body mass, urine pH, urine concentration and other medical conditions such as kidney or liver disease.
How much THC needs to be present to cause a positive drug test?
Drug tests either test for the parent drug or at least one of its metabolites, or both. Concentrations of drugs in urine are usually higher than in blood and present for longer.
Federal workplace cutoff values for marijuana metabolites are 50 ng/mL for immunoassay screening tests (one ng is a billionth of a gram). In a confirmatory test, a metabolite of marijuana is measured, called delta-9-tetrahydrocannabinol-9-carboxylic acid, and a positive test result is above 15 ng/mL. However, this can vary depending on the variables listed above and should not be relied upon to ensure a drug-free result.
Confirmatory tests (Drug of Abuse Panel tests) use gas chromatography/mass spectrometry to identify specific molecular structures and to quantify the amount of drug or a substance present in the sample. These are more accurate than screening tests, but are also more costly and time-consuming and are usually reserved for situations that have significant legal, academic, forensic, or employment sequelae. These recognize cannabinoids rather than metabolites so should be able to distinguish CBD from THC.
Medically reviewed by Carmen Fookes, BPharm. Last updated on Oct 30, 2019.
If you are concerned that THC in your CBD oil or other CBD product may show up on a drug test, you may be able to reduce the chance of that occurring, though there is no guarantee. Some of the factors that may increase the likelihood of a failed drug test are:
CBD products can still be problematic, however, when it comes to drug testing. Though drug tests screen for THC, not CBD, many CBD products contain a trace amount of THC which will be detected in your bloodstream during a drug test.
Topical products that claim to contain CBD—like shampoos, cosmetics or creams—should not cause any reaction during a drug test because they do not enter the bloodstream. In the case of CBD oils, gummies, teas or transdermal patches, the situation is more complicated. In a test of 84 CBD products obtained online, 18 contained THC.
Factors in CBD Oil Showing on Drug Screen
The legality of CBD products can be confusing. CBD products made from certain cannabis plant varieties are legal only in states where marijuana is legal, due to the potential THC content. CBD products made from hemp variety plants are legal throughout the United States as long as they contain less than 0.3% of THC and do not make any medical claims. (A hemp plant is defined as Cannabis sativa that contains less than 0.3% THC.)
THC can be detected in a urine test for up to 15 days, depending on how often and how much you use. It leaves the bloodstream in about five hours, but substances your body makes from THC (THC metabolites) can show up for as long as 7 days. CBD tends to stay in the bloodstream from 2 to 5 days, depending on dosage and frequency. If you have been using CBD for a while, it can stay in your body for up to 30 days or more.
CBD has taken off as a natural remedy for a variety of ailments. CBD products like CBD oil can be made from either the hemp plant or the cannabis plant, which are closely related varieties of the same cannabis species, Cannabis sativa. CBD products contain a cannabinoid—a chemical—called cannabidiol, which does not make you high. The substance in marijuana that causes a buzz is a different cannabinoid, called THC, or tetrahydrocannabinol.
CBD will not show up in a drug test because drug tests are not screening for it. CBD products may well contain THC, however, so you can fail a drug test after taking CBD products. If you take CBD oil, you should plan accordingly if your work or activities require you to undergo drug testing.