Article published with permission of USADA
Tetrahydrocannabinol (THC) is the active component in marijuana (e.g., hashish, pot, weed, etc.) which comes from the marijuana plant (Cannabis sativa) and produces the “high”. THC is prohibited in-competition by the World Anti-Doping Agency (WADA). When an athlete is tested in-competition, their urine is screened for the presence of THC.
There are many nutritional products on the market that advertise to contain hemp, hemp seed oil, or other parts of the marijuana plant. Since it is plant-based, hemp protein is marketed as a good source of protein for vegans. It is also appearing in more mainstream food products such as some brands of yogurt.
Under ideal circumstances, the parts of the plant used for hemp (the stem and seeds) do not contain THC. Most growers of hemp purposely grow plants low in THC concentration so that they can harvest the stems, oil, and seeds without worrying about legal issues around THC content. However, some stems and seeds that are harvested for the hemp protein do contain detectable amounts of THC. Furthermore, some hemp suppliers are not always careful about the part of the plant that they harvest, or even which plant they harvest. Hemp suppliers do not always test their products for THC content so they may not realize they are selling hemp with detectable levels.
Athletes need to be aware that while some papers show that the likelihood of testing positive from a hemp product (at least in workplace testing) is very low, there are at least two peer-reviewed articles that show it is possible to sometimes detect THC in the urine of people who have consumed hemp products. Athletes that choose to consume hemp products may be at risk for a positive antidoping test, even though many of these products claim to not contain THC. Thus, the risk of testing positive from hemp is low, but nonetheless it may be possible. Because athletes are strictly liable for what is in their system, irrespective of how it got there, it is very important to be aware of this possibility.
There are many factors that influence whether THC is detectable in a urine sample which may lead to a positive test, such as the time of the test in relation to consumption of the substance, concentration of THC in the hemp product, and the weight and metabolic rate of the individual. Just because a friend uses the same hemp product, is tested, and receives a negative test result, doesn’t mean that the athlete is safe. The consumption of products containing hemp is at the athlete’s own risk.
For those athletes also enlisted in the military, some services have strict rules about consuming hemp. They will need to contact a representative at their service branch for more information.
1. Leson, G., Pless, P., Grotenhermen, F., Kalant, H. and ElSohly, M. A. Evaluating the impact of hemp food consumption on workplace drug tests. (2001). J Anal Toxicol, 25:691-8. http://www.ncbi.nlm.nih.gov/pubmed/11765026
2. Yonamine, M., Garcia, P. R. and de Moraes Moreau, R. L. Non-intentional doping in sports. (2004). Sports Med, 34:697-704.