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Marijuana FAQ

Your Questions Answered

USADA is a signatory to the World Anti-Doping Code, which, along with the Prohibited List and the International Standard for Therapeutic Use Exemptions, is created and maintained by the World Anti-Doping Agency (WADA) in order to harmonize anti-doping efforts around the world across all sports.

The WADA Prohibited List establishes marijuana and cannabinoids as substances that are prohibited in-competition. The use of prohibited substances in sport, without an approved Therapeutic Use Exemption (TUE), may lead to an anti-doping rule violation and sanction. Recently, some states have passed laws decriminalizing the use of recreational marijuana, resulting in questions from both athletes and the public alike regarding marijuana and anti-doping rules.

Below, you’ll find detailed answers regarding marijuana’s position on the Prohibited List and its adverse effects on athletes, synthetic cannabinoids, information on Federal and State marijuana legislation in the United States, and the role of medical marijuana within the TUE process. We encourage you to read on and familiarize yourself with the rules and laws referenced on this page. USADA is always available to help with any questions you may have about marijuana and cannabinoids, and can be contacted via phone at 1-866-601-2632 or email at athleteexpress@USADA.org.

Answers to Common Questions regarding Marijuana and Cannabinoids

The WADA Prohibited List is the international standard for identifying substances and methods prohibited in sport. The List is updated annually and a substance will be considered for the List if it meets any two of the following three criteria:

  1. It has the potential to enhance or enhances sport performance.
  2. It represents an actual or potential health risk to the athlete.
  3. It violates the spirit of sport.

The annual decision to include or not include a substance or method on the Prohibited List is the responsibility of the WADA Prohibited List Committee based on current scientific and medical knowledge and the input from all stakeholders during an annual consultation process. Since the inception of the Prohibited List in 2004, marijuana and cannabinoids have been prohibited in-competition.

Why might marijuana and cannabinoids meet this criteria?

  • Performance-enhancement: A common perception of marijuana is that its use impairs physical activity, including exercise performance. While the effects of marijuana can decrease hand-eye coordination and distort spatial perception, there are other effects that can be performance enhancing for some athletes and sport disciplines. Cannabis can cause muscle relaxation and reduce pain during post-workout recovery. It can also decrease anxiety and tension, resulting in better sport performance under pressure. In addition, cannabis can increase focus and risk-taking behaviors, allowing athletes to forget bad falls or previous trauma in sport, and push themselves past those fears in competition.[1]
  • Actual or potential health risk: A number of studies show that marijuana use may cause a variety of health risks. These risks include negative effects on respiratory, cardiac, and mental health. Frequent marijuana smokers can experience respiratory problems including more frequent acute chest illness and a heightened risk of lung infections. Marijuana use raises the heart rate by 20-100 percent shortly after smoking which can increase the risk of heart attack. Chronic marijuana use has also been linked to mental illness including paranoia and psychosis.[2]
  • Violation of the spirit of sport: Negative values and ethics included in sport, and beyond sport, are considered in this criteria. Due to the illegal nature of marijuana in most countries, the use or abuse of marijuana does not exhibit the ethics and moral judgment that upholds the spirit of sport.[1]


  1. Cannabis in Sport: Anti-Doping Perspective. http://www.ncbi.nlm.nih.gov/pubmed/21985215
  2. National Institute on Drug Abuse. http://www.drugabuse.gov/publications/drugfacts/marijuana

Although the smoke of marijuana and tobacco both consist of a mixture of toxic gases, marijuana smoke inhalation can be more harmful than tobacco smoke.[1] [2] Marijuana smoke can deliver 50-70% more carcinogens to the lung.[2] [3] When smoked in the form of a cigarette, cannabis is less densely packed when compared to tobacco cigarettes and tends to be smoked without a filter.[3] They are also smoked to a smaller butt size and this can lead to higher concentrations of inhaled smoke.[3] Although on a daily basis, a fewer number of marijuana cigarettes are generally smoked when compared to tobacco, it must be noted that there are different methods to inhale marijuana.[1] Additionally, cannabis smokers tend to inhale deeper and hold their breath for longer when compared to tobacco smokers.[3] This allows for the deposition of the carcinogenic gases and products even in the regions of the lower lungs.[3] Despite the carbon monoxide concentrations in the inhaled smoke of both being similar, the above factors are likely to be responsible for the increased absorption of carbon monoxide and other smoke irritants in cannabis.[3]

A population-based case-control study interprets that for each joint-year (one joint smoked a day for 365 days straight) of exposure to cannabis in young adults, the risk of lung cancer increases by an estimated 8%.[3] It was also observed that smoking one joint of cannabis was similar to smoking 20 tobacco cigarettes in terms of risk of lung cancer.[3] A few key DNA repair enzymes have also been shown to be inhibited by cannabinoids.[5] Cannabis also plays a role in the stimulation of cell development and malignant cell growth.[5] Thus, cannabis has been implicated in uncontrolled cell growth and of the impairment of DNA replication and repair, which are likely indicators of cancer.[5]

Marijuana, or cannabis, is the second most commonly smoked substance after tobacco in a number of societies.[1]

Some physical effects of cannabis smoking include, decreased immune function, higher rates of irregular heartbeat, and stroke.[2] Cannabis smoking has also been associated with mental conditions such as depression, psychosis, bipolar disorder, and anxiety.[4] Respiratory conditions including lung cysts, chronic bronchitis, and lung cancer have been linked to the inhalation of marijuana smoke.[4] [5]


  1. Tashkin, TD. Smoked marijuana as a cause of lung injury. Monaldi Arch Chest Dis. 2005 Jun;63(2):93-100. http://www.ncbi.nlm.nih.gov/pubmed/16128224
  2. McGuinness, TM. Update on marijuana. J Psychosoc Nurs Ment Health Serv. 2009 Oct;47(10):19-22. http://www.ncbi.nlm.nih.gov/pubmed/19835316
  3. Aldington, S, et al. Cannabis use and risk of lung cancer: A case-control study. Eur Respir J. 2008 February; 31(2): 280–286. http://www.ncbi.nlm.nih.gov/pubmed/18238947
  4. Reece, AS. Chronic toxicology of cannabis. Clin Toxicol (Phila). 2009 Jul;47(6):517-24. http://www.ncbi.nlm.nih.gov/pubmed/19586351
  5. Reece, AS. Cannabis and lung cancer. Eur Respir J. 2008 Jul;32(1):238-9. http://www.ncbi.nlm.nih.gov/pubmed/18591344

Marijuana (cannabis) use can produce psychological and biological changes, as well as changes to human behavior. Tetrahydrocannabinol, or THC, is the main psychoactive drug in cannabis. However, there are other cannabinoids which also contribute to its biochemical effect.[1]

The behavioral effects of cannabis are dose-dependent, and can include:

  • Mood changes
  • Paranoia
  • Sedation
  • Impaired movement

Severe intoxication due to cannabis consumption can lead to short-term memory impairment. Some of the negative physical effects of cannabis use include dry mouth and throat, an increased resting heart rate, and the expansion of both lung passageways and blood vessels. Cannabis smoking can also produce rapid changes to heart rate, dizziness, and low blood pressure.[1]

A 2014 United Nations Office on Drugs and Crime report found that in the United States, between 2006 and 2010, there was a 59% increase in cannabis-related emergency room visits and a 14% increase in cannabis-related hospital admissions.[3]

One of the criteria for a substance, or method, to be included on the WADA Prohibited List is its potential health risk to the athlete. Cannabis use can alter the perception of risk, thus potentially leading to poor decision making. It may also impair essential technical skills of the athlete, thus leading to a higher probability of accidents and injuries. Cannabis use may also negatively influence coordination, movement, and time estimation. All these effects may pose a risk for the athlete and others, especially in sports which involve handling equipment or high speeds.[1]

Synthetic cannabinoids also pose a great risk to users and athletes. While synthetic cannabinoids may produce effects similar to marijuana, their severity could be greater than those produced by marijuana. When compared to THC, some of the compounds found in synthetic cannabinoids bind more strongly to receptors within the brain. This reaction could lead to potentially more powerful and unpredictable effects. Since synthetic cannabinoid products may not list all of their ingredients on the packaging label, the effects of the product could be different than what the user may expect.[2]


  1. Huestis MA, et al. Cannabis in sport. Sports Med 2011; 41 (11): 949-966
  2. National Institute on Drug Abuse. http://www.drugabuse.gov/publications/drugfacts/spice-synthetic-marijuana
  3. United Nations Office on Drugs and Crime. http://www.unodc.org/documents/wdr2014/Cannabis_2014_web.pdf

Marijuana refers to the dried leaves, seeds, flowers, and stem from the cannabis plant. It contains the psychoactive chemical tetrahydrocannabinol, or THC. The chemical structure of THC is similar to a chemical in the body. Due to the similarity in structure, drugs can be recognized by the body and can alter normal brain communication.[1] Marijuana use may induce a wide range of negative health effects, particularly on cardiac and mental health.[1] Some of these include respiratory problems, an increased risk of lung infections, and heart attacks, depression, and anxiety.

Synthetic or designer drugs that are chemically similar to THC are called synthetic cannabinoids. While these drugs are similar to THC at a molecular level, athletes need to be aware that their negative effects may be more severe and can result in serious health consequences.[2]

Some of the names that synthetic cannabinoids are commonly sold as include:

  • ‘Spice’
  • ‘K2’
  • ‘Cloud 9’
  • ‘Relax’
  • ‘Mojo’
  • ‘Crown’, among others.

Consumption of these synthetic cannabinoids has resulted in numerous hospitalizations. [2] These drugs have been reported to cause hallucinations, increased heartbeat and blood pressure, aggressive behavior, anxiety, muscle spasms, nausea, and vomiting.[2]

The use and production of synthetic cannabinoid products have increased over the past few years.[3] These products may be marketed as herbal mixtures, incense, or potpourri. The packaging labels of these products may list only natural herbs as ingredients, but analysis has revealed that they contain synthetic cannabinoids.[3] Smoking these products can produce psychoactive and physical effects, behavioral disturbances, anxiety, and negative alterations in mood.[4]


  1. National Institute on Drug Abuse. http://www.drugabuse.gov/publications/drugfacts/marijuana
  2. Synthetic cannabinoid use: recognition and management. http://www.ncbi.nlm.nih.gov/pubmed/22418399
  3. Notes from the Field: Increase in Reported Adverse Health Effects Related to Synthetic Cannabinoid Use — United States, January–May 2015. http://www.cdc.gov/mmwr/preview/mmwrhtml/mm6422a5.htm
  4. National Institute on Drug Abuse. http://www.drugabuse.gov/drugs-abuse/emerging-trends

In 1970, the United States federal government enacted the Controlled Substances Act (CSA). This act determined that marijuana (cannabis) is a Schedule I controlled substance.[1] A Schedule I substance is defined as follows:

  1. The drug or other substance has a high potential for abuse.
  2. The drug or other substance has no currently accepted medical use in treatment in the United States.
  3. There is a lack of accepted safety for use of the drug or other substance under medical supervision.[2]

Recently, a handful of states, including Colorado, Alaska, Oregon, and Washington, have passed laws legalizing marijuana for personal, recreational use. These state laws do not change the fact that the United States recognizes marijuana as a dangerous drug, and to possess, manufacture, and/or distribute marijuana is a crime under Federal law.[3] The Department of Justice plans to continue to enforce the CSA nationwide.[1] As a signatory to the World Anti-Doping Code, USADA adopts and follows the WADA Prohibited List. Since marijuana is listed on the Prohibited List as a prohibited substance in-competition, U.S. athletes have to comply, irrespective of their State laws.


  1. Office of National Drug Control Policy. http://www.whitehouse.gov/ondcp/frequently-asked-questions-and-facts-about-marijuana
  2. U.S. Department of Justice: Office of Diversion Control. http://www.deadiversion.usdoj.gov/21cfr/21usc/812.htm
  3. Office of National Drug Control Policy. http://www.whitehouse.gov/ondcp/state-laws-related-to-marijuana

Will USADA consider a Therapeutic Use Exemption (TUE) application for medical marijuana?

USADA will consider a TUE application for medical marijuana, but only for certain conditions as per the WADA TUE Physician Guidelines for Neuropathic Pain.

There are also a number of additional important factors to consider. Most importantly, submitting a TUE application for medical marijuana which has been prescribed by a physician does not guarantee the TUE will be approved. All approved TUEs for cannabis or other FDA-approved cannabinoid medication must meet all the criteria set forth in the International Standard for TUEs.

There are some medically approved uses for some synthetic compounds that are also found in the marijuana plant including the substance dronabinol (marketed as Marinol in the USA). This medication is prescribed according to strict criteria and only for certain illnesses (i.e. cancer, AIDS).

To be considered a safe and legitimate medicine in the United States, a substance must be approved by the Food and Drug Administration (FDA). An approved substance must have consistent, well-defined and measurable ingredients that pass rigorous clinical trials.

The urinary threshold level for the cannabis metabolite Carboxy-THC is 150ng/mL, and WADA accredited laboratories are not required to report adverse analytical findings below this level. Carboxy-THC, also known as 11-nor-9-Carboxy-THC, 11-nor-9-carboxy-delta-9-tetrahydrocannabinol, 11-nor-9-carboxy-delta-9-THC, 11-COOH-THC, or THC-COOH, is the main secondary metabolite of tetrahydrocannabinol (THC) which is formed in the body after cannabis is consumed.

This new level was approved by the WADA Executive Committee in May 2011. There are no urinary threshold limits for other synthetic cannabinoids, meaning detection of any amount will be reported.

Cannabinoids are prohibited in-competition. This includes natural cannabinoids (e.g. cannabis, hashish and marijuana) and synthetic cannabinoids (e.g. THC and “Spice”).

It’s the athlete’s responsibility to ensure that they do not ingest prohibited substances.

Because cannabis is prohibited only in-competition, many athlete inquiries to USADA ask how long cannabis will remain in their system following “recreational use” out-of-competition. This is an extremely complex question to answer, and USADA cannot make estimates for athletes. As an elite athlete who is subject to rules of sport, including anti-doping rules, the easiest answer is not to ingest cannabis in the first place.

The clearance time of a substance is the time taken for the substance to be completely eliminated from the body. This clearance time can vary between individuals and can depend on various factors such as metabolism rate and the build up of the substance in fatty tissue. Marijuana is an example of a slow metabolizer and could take weeks or months to clear completely from an athlete’s body, depending how it is consumed. Other factors that could impact the metabolism rate of marijuana are the quality, potency, and concentration of the product.

It is very important for an athlete to recognize and understand that they are strictly responsible for what is found in their bodies. As such, understanding clearance times of substances becomes essential, especially if the substance is prohibited only in-competition. If an athlete partakes in the substance out-of-competition, and that substance is still present in their body when tested at a competition, they may be held responsible for an anti-doping rule violation.

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