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.
An estimate of the length of time marijuana (THC) is detectable in urine is:
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.
There are two main types of urine drug tests: screening and confirmatory tests. Immunoassay screening tests can be conducted on-site (point of care testing) or in a laboratory and allow large numbers of tests to be performed at once with relatively rapid results, providing an initial estimate of the presence or absence of drugs. There are three main types available, and all use antibodies to detect the presence of specific or classes of drug metabolites. Unfortunately, this can mean that substances with similar characteristics may be detected, resulting in false-positive results.
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.
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 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.
Factors in CBD Oil Showing on Drug Screen
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.
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 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.
When a drug test is performed, the active chemical in marijuana that gets detected in a positive screening is THC. However, most people are under the impression that CBD oil is THC-free.
There are several techniques for extracting CBD oil from the cannabis plant. The extraction method determines whether the active CBD compound gets processed as a “full spectrum oil” or an “isolate.” A CBD isolate is a pure compound with no other active compounds or cannabinoids at all. A full spectrum oil contains other active plant compounds in addition to the CBD such as CBN (cannabinol) and cannabis terpenes (the part of the plant that gives the plant its aroma), and more.
Breakdown of Cannabis
Some sources report that in rare cases, false positive test results have come from CBD oil that breaks down into very small amounts of THC in the stomach. Other studies, however, have refuted this.
Cannabis is the umbrella term describing hemp and marijuana plants—two different varieties of the cannabis genus. Both marijuana and hemp can be described as cannabis plants; however, it is important to note that they are still two separate plants.
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.