• Cannabidiol (CBD) does not show up on a drug test, but delta-9-tetrahydrocannabinol (THC) may show up. While the allowed THC content is not more than 0.3%, the volume may accumulate with frequent use, enough to be detected on a drug test(1)
  • CBD products may also contain trace amounts of THC. For instance, the full-spectrum variety contains all cannabinoids or compounds from hemp or marijuana, including THC.
  • CBD is a non-psychoactive compound more abundant in hemp, while THC is the major psychoactive component of marijuana or cannabis, which induces euphoric effects(2).
  • Urine test is the most common drug test, which checks for the presence of THC metabolites. Other drug screening methods test blood, saliva, and hair(3).
  • CBD users should carefully read product labels, conduct research, and consult a doctor before purchasing CBD products to avoid getting a false-positive result on a drug test.


CBD is a cannabinoid or compound found in a cannabis plant—marijuana or hemp. However, it is more abundant in hemp.

CBD does not make users feel high because it is a non-psychoactive compound. It is also well tolerated in clinical trials(4).

Although research on CBD use is still inconclusive, this compound is gaining popularity because of its suggested therapeutic and medical benefits, including pain relief and treatment for medical conditions, like anxiety, epilepsy, and schizophrenia(5).

Still, CBD may have adverse side effects, such as diarrhea, dry mouth, and fatigue(6).

THC is the main psychoactive compound present in marijuana or cannabis. Hence, it causes a euphoric feeling among CBD users.

THC also showed promising therapeutic benefits in chronic pain, chemotherapy-induced nausea and vomiting, and patient-reported spasticity symptoms associated with multiple sclerosis(7).

However, THC may cause altered time perception, cognitive impairment, and memory and mood changes. THC may also cause rapid changes in heart rate and blood pressure, and dry mouth and throat(8).

As THC is psychoactive, it is one of the compounds targeted in drug tests, and enough THC leads to a positive drug test result.

Thus, users should consult a health professional before taking CBD and THC products to make well-informed decisions.

Types of CBD

CBD products have three varieties: full-spectrum, broad-spectrum, and CBD isolates. Users should know their differences to pick the right CBD product based on their needs.

Full-spectrum CBD contains terpenes, flavonoids, and all cannabinoids, such as CBD, cannabinol (CBN), and the psychoactive compound, THC.

Terpenes are cannabis compounds responsible for the plant’s aroma and flavor, while flavonoids are responsible for most plants’ vivid colors. When these compounds interact, they produce an “entourage effect,” proven to be more efficient than isolated compounds(9)

Broad-spectrum CBD is like full-spectrum CBD, except that it does not contain THC. Thus, users who do not want THC’s euphoric effects can buy broad-spectrum CBD products.

Broad-spectrum CBD may also produce the entourage effect as it contains different cannabinoids.

Meanwhile, CBD isolates are pure CBD extracted in isolation from all cannabinoids. Thus, it contains zero percent THC.

This variety allows users to take advantage of the full benefits of CBD. However, CBD isolate products do not produce the entourage effect.

CBD products are available in different forms, including tinctures, vapes, topicals, supplements, and edibles.

CBD users may still get a false-positive result in drug tests, as other varieties contain THC, the psychoactive compound in cannabis plants.

Hemp CBD Oil vs. Cannabis CBD

Hemp CBD oil differs from cannabis CBD. Hemp CBD oil comes from industrial hemp plants grown mainly for their fiber and seeds.

Hemp oil and other hemp products are federally legal, so long as the THC level is not more than 0.3%(10).

Meanwhile, cannabis CBD comes from marijuana plants or cannabis, which has large, resinous bud and aromatic leaves, generally consumed for the plant’s intoxicating properties.

While the 2018 Farm Bill removes hemp from the Controlled Substances Act (CSA), it retains the authority of the Food and Drug Administration (FDA) to regulate products containing cannabis or cannabis-derived compounds(11)

Products with more than 0.3% THC are classified as Schedule I drugs. Currently, the FDA approves the use of Epidiolex, Marinol, Syndros, and Cesamet only.

Epidiolex is used to help treat seizures associated with Lennox-Gastaut syndrome or Dravet syndrome, two rare types of epilepsy.

Marinol and Syndros contain dronabinol, a synthetic THC, approved in treating anorexia associated with weight loss in AIDS.

Lastly, Cesamet is synthetically derived and contains nabilone, which has a chemical structure similar to THC

As cannabis CBD contains more THC, it is often considered illegal. Thus, users should only buy cannabis products in states where marijuana use is allowed for recreation and medical purposes.

Drug Screening Methods

Along with the legalization of medical marijuana and recreational marijuana in some states, drug use tests are conducted in workplaces, especially in the United States.

There are different drug screening tests, the most common being the urine test, which checks for THC metabolites. Other drug screening methods include a saliva test, hair test, and blood test.

Urine Test

Urine drug test remains the most common method to detect drugs in the human body. This test is based on immunoassay techniques that detect a substance’s presence or quantity based on its capacity as an antibody. 

Substances tested in a urine sample include alcohol, amphetamines, benzodiazepines, opiates/opioids, cocaine, and cannabis(12).

However, urine tests do not detect THC, the psychoactive component in marijuana. Rather, they detect THC-COOH, the non-psychoactive marijuana metabolite that can remain in the body for days and weeks but has no impairing effects(13).

THC-COOH triggers a positive drug test result if its concentration is 50 nanograms per milliliter (ng/ml)(14).

It often takes two hours for a substance to be detected in the urine(15). The detection window varies depending on the dose and frequency of use.

Different factors can affect the results, like urine pH, fluid intake, body mass, and other medical conditions, like kidney and liver disease.

Saliva Test 

To date, saliva tests are still uncommon. These tests generally detect concentration correlated with plasma concentrations.

Unlike urine testing that focuses more on metabolite concentrations, like THC-COOH, saliva testing is more likely to detect parent compounds, like THC(16).

There are no established cut-off values for detecting THC in saliva. However, an article from the Journal of Medical Toxicology stated that the suggested initial screen cutoff is 4ng/ml, and the confirmation cutoff is 2ng/ml(17).

While urine testing is more common than saliva testing, one study showed that patients and staff preferred saliva testing. It is less time-consuming and helps maintain one’s dignity, despite being more costly(18).

Hair Test

Like saliva testing, hair testing is also uncommon. However, it can provide information on cumulative substance use.

This screening test can be used to detect cocaine, amphetamines, and opioids.

Currently, there are no set cut-off values for detecting THC in hair.

The detection window of hair testing is also long. For instance, the scalp hair’s detection window is three months, while slower-growing body hair’s detection window can last up to one year(19).

Also, hair test results can vary per individual, depending on the condition of one’s hair.

Blood Test

Blood testing is the least common drug screening method for THC. It is performed in emergency situations and is used to detect ethanol leaves.

With this drug test, it is highly unlikely to get a false-positive result.

However, compared to urine, saliva, and hair testing, blood testing is limited as the compound immediately leaves the bloodstream after use. Blood testing typically detects substance use within 2 to 12 hours of the test(20).

Also, this drug test needs a medical expert to obtain the sample. The sample itself can be a potential biohazard too.

How Do Drug Tests for Cannabis Work?

Drug tests for cannabis work differently, depending on the screening method used. For instance, urine tests target metabolites of drugs such as amphetamines, benzodiazepines, opiates, cocaine, and cannabis.

Urine testing involves two types: immunoassay screening and confirmatory tests. Immunoassay screening tests can be conducted on-site or in a laboratory. 

This type of urine testing quickly provides an initial estimate of drugs’ presence or absence and can handle many tests.

However, immunoassays detect substances with similar characteristics, resulting in cross-reactivity leading to false-positive results(21).

Meanwhile, confirmatory tests use gas chromatography or mass spectrometry to determine the specific molecular structures and the amount of the substance present in the urine sample.

Possible Reasons Behind Failing a Drug Test

According to the Substance Abuse and Mental Health Services Administration (SAMHSA), inaccurate testing can be prevented by using a Health and Human Services (HHS)-certified laboratory, such as LabCorp, and a Medical Review Officer (MRO) to interpret drug test results(22).

A negative result from a drug test does not indicate that one has never used alcohol drugs. It is also not a guarantee against future drug use. 

Rather, a negative result means that the use of THC or other substances is lower than the cut-off value.

Cross-contamination can cause a negative test result. This incident is possible during the CBD manufacturing process in which products containing CBD only, THC only, or a combination of both are prepared.

Incorrect product labeling may also be another reason. As the FDA does not regulate the use of CBD products, lab testing is necessary to ensure safety.

It is highly unlikely to get a positive drug test result from secondhand exposure to marijuana. However, a study showed that the amount of THC inhaled from secondhand smoking depends on the potency of marijuana and the smoking area’s ventilation(23).

Some precautions can be taken to avoid getting a false-positive test result on drugs. Although CBD does not show up on a drug test, some CBD products contain THC that may produce a positive test result.

Choosing Which CBD Products to Buy

CBD products are classified as full-spectrum, broad-spectrum, and CBD isolates. CBD isolates are pure CBD, so these products are THC-free.

Broad-spectrum CBD contains all cannabinoids, including CBD, terpenes, and flavonoids, except for THC. Thus, users of these products should not need to worry about getting a positive test result for THC, although this may not be guaranteed.

However, the full-spectrum CBD products contain all cannabinoids, including THC. While the required levels of THC are not more than 0.3%, frequent use of these products may create the risk of testing positive on a drug test.

Hence, CBD users should consult a doctor to ensure that they are not using these products excessively.

Read Product Labels 

CBD products include labels that allow users to determine whether the product is derived from hemp or marijuana. 

Users should also check the label to determine whether the CBD is full-spectrum, broad-spectrum, or CBD isolate. They should see if the product contains THC, which is the compound often detected in different drug tests

Conduct Research

Users of CBD products should research before purchase. For instance, they should find out the source of hemp.

They can check the brand’s website to know the extraction method used. Also, these CBD products should be free from pesticides, solvents, and other harmful substances. 

Most importantly, users should take CBD products that undergo third-party lab testing to ensure their safety.

Future of CBD Drug Testing

Drug tests do not target CBD as it is non-psychoactive; rather, they aim to detect THC and other substances. However, drug testing in workplaces may decrease in the future.

With federal bills, like the Marijuana Opportunity Reinvestment and Expungement Act of 2019 or MORE Act, the use of cannabis products may be decriminalized and descheduled(24). Also, other states allow recreational use or medical use of marijuana.


CBD does not show up on a drug test, but THC may show up due to frequent use. Some CBD products may also contain small amounts of THC, the psychoactive compound targeted in drug tests.

Hemp CBD oil is derived from hemp and contains more CBD, while cannabis CBD is derived from marijuana and contains more THC

Urine test is the most common drug screening method, which checks for THC metabolites called THC-COOH. Other tests use hair, blood, and saliva as samples.

To avoid getting false-positive drug test results while taking CBD products, users should check product labels, research about the brand, and check if the products are safe and tested.

  1. U.S. Food and Drug Administration. (2020, Oct. 1). FDA Regulation of Cannabis and Cannabis-Derived Products, Including Cannabidiol (CBD). Retrieved from https://www.fda.gov/news-events/public-health-focus/fda-regulation-cannabis-and-cannabis-derived-products-including-cannabidiol-cbd 
  2. Russo E. B. (2008). Cannabinoids in the management of difficult to treat pain. Therapeutics and clinical risk management, 4(1), 245–259. https://doi.org/10.2147/tcrm.s1928 
  3. McNeil SE, Cogburn M. Drug Testing. [Updated 2020 Jun 3]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2020 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK459334/ 
  4. Russo E. B. (2008). Cannabinoids in the management of difficult to treat pain. Op Cit. 
  5. Shannon, S., Lewis, N., Lee, H., & Hughes, S. (2019). Cannabidiol in Anxiety and Sleep: A Large Case Series. The Permanente journal, 23, 18–041. doi.org/10.7812/TPP/18-041. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6326553/ 
  6. Education Collaboration Hope. (2017, Apr. 18). A Look at the Endocannabinoid System’s CB1 and CB2 Receptors. Retrieved from https://echoconnection.org/look-endocannabinoid-systems-cb1-cb2-receptors/
  7. National Academies of Sciences, Engineering, and Medicine; Health and Medicine Division; Board on Population Health and Public Health Practice; Committee on the Health Effects of Marijuana: An Evidence Review and Research Agenda. The Health Effects of Cannabis and Cannabinoids: The Current State of Evidence and Recommendations for Research. Washington (DC): National Academies Press (US); 2017 Jan 12. 4, Therapeutic Effects of Cannabis and Cannabinoids. Available from: https://www.ncbi.nlm.nih.gov/books/NBK425767/ 
  8. Sharma, P., Murthy, P., & Bharath, M. M. (2012). Chemistry, metabolism, and toxicology of cannabis: clinical implications. Iranian journal of psychiatry, 7(4), 149–156. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3570572/ 
  9. Russo E. B. (2008). Cannabinoids in the management of difficult to treat pain. Op Cit.
  10. U.S. Food and Drug Administration. (2020, Oct. 1). FDA Regulation of Cannabis and Cannabis-Derived Products, Including Cannabidiol (CBD). Op Cit.
  11. Ibid.
  12. McNeil SE, Cogburn M. Drug Testing. [Updated 2020 Jun 3]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2020 Jan. Available from: https://www.ncbi.nlm.nih.gov/books/NBK459334/ 
  13. California NORML. (2017, Feb. 25). Marijuana Drug Test Detection Times. Retrieved from https://www.canorml.org/employment/marijuana-drug-test-detection-times/ 
  14. Kulig K. (2017). Interpretation of Workplace Tests for Cannabinoids. Journal of medical toxicology : official journal of the American College of Medical Toxicology, 13(1), 106–110. doi.org/10.1007/s13181-016-0587-z. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5330962/ 
  15. McNeil SE, Cogburn M. Drug Testing. [Updated 2020 Jun 3]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2020 Jan. Available from: https://www.ncbi.nlm.nih.gov/books/NBK459334/ 
  16. Ibid. 
  17. Kulig K. (2017). Interpretation of Workplace Tests for Cannabinoids. Op Cit. 
  18. McNeil SE, Cogburn M. Drug Testing. [Updated 2020 Jun 3]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2020 Jan. Available from: https://www.ncbi.nlm.nih.gov/books/NBK459334/ 
  19. Ibid. 
  20. Hadland, S. E., & Levy, S. (2016). Objective Testing: Urine and Other Drug Tests. Child and adolescent psychiatric clinics of North America, 25(3), 549–565. https://doi.org/10.1016/j.chc.2016.02.005 
  21. Mayo Clinic. (2017, Mar. 18). Clinical Interpretation of Urine Drug Tests: What Clinicians Need to Know About Urine Drug Screens. Retrieved from https://www.mayoclinicproceedings.org/article/S0025-6196(16)30825-4/fulltext#sec2.1 
  22. Substance Abuse and Mental Health Services Administration. (200, Apr. 30). CDrug Testing. Retrieved from https://www.samhsa.gov/workplace/resources/drug-testing 
  23. National Institutes of Health. (2020, Jul). Marijuana Research Report. Retrieved from https://www.drugabuse.gov/publications/research-reports/marijuana/what-are-effects-secondhand-exposure-to-marijuana-smoke 
  24. Congress Gov. (2019, Nov. 21). H.R.3884 – Marijuana Opportunity Reinvestment and Expungement Act of 2019. Retrieved from https://www.congress.gov/bill/116th-congress/house-bill/3884/text?q=%7B%22search%22%3A%5B%22%5C%22more+act%5C%22%22%5D%7D&r=5&s=1 
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