One of the biggest obstacles to responsible proponents of medical cannabis is the amount of misinformation we have to contend with from both sides. On one side there are government-sponsored publications that directly misconstrue the science behind cannabis. On the other, there are well-meaning citizens of the cannabis community that get carried away. To their credit, cannabis *is* a magical Swiss Army Knife of a plant. The amount of uses for cannabis from medical to industrial is mind-boggling; humanity has always had a special relationship to the plant, which is evident in some of the oldest Chinese characters. However, in the tide of wanting to support positive change and wanting modern society to see the truth about such a useful plant, some sources are too lenient on fact checking. For instance, someone who reads a study stating cannabis components kill cancer cells in a rat tumor, concludes that smoking cannabis cures cancer, and proceeds to distribute that viewpoint throughout the community. The truth is cannabis does hold answers to new chemotherapy drugs which may be used in conjunction with other treatments, but that’s obviously not the same as saying it is a cure for cancer. Overly-hopeful supporters of cannabis need to be carful not to unintentionally harm the integrity of the movement.
This “hype” effect is especially pronounced in the case of tetrahydrocannabivarin (THCV). Just like the name sounds, this is a chemical cousin of THC, the principal psychoactive component of cannabis. However, there are a few key functional differences. First, THC has a five-carbon atom group, whereas THCV has a three-carbon atom group. This structure changes how the molecule interacts with cannabinoid receptors. In the case of THC, the molecule is a partial agonist of CB1 and CB2 receptors, which means it activates both and is subsequently broken down. In the case of THCV, the molecule is a partial agonist outside its normal biological environment, but inside the body, it’s a strong antagonist of cannabinoid receptors. In other words, it blocks receptors and is the opposite of signaling those receptors with THC.
This is the reason that THCV has drawn so much hype as a weight loss supplement. Numerous well-respected sites express the viewpoint that THCV can be part of a healthy weight loss strategy and back that position up with studies showing THCV to decrease appetite. This part is true. THCV, alone, does decrease appetite and stimulate weight loss, as seen in numerous studies. However, what these sites aren’t explaining is that the health utility of THCV to humans is not such a simple matter. Regular readers will remember previous mentions of Rimonabant, a failed pharmaceutical similar to THCV. Observing that cannabinoid receptor agonists (like THC) could lead to appetite stimulation, and the reverse, that cannabinoid receptor antagonists (like THCV) could lead to appetite suppression, Sanofi-Aventis began developing synthetic antagonists and running human trials. These trials didn’t raise any obvious red flags at first, and as a result, in 2006 the European Commission approved the first legal use of a Rimonabant, a cannabinoid receptor antagonist for extreme cases of obesity.
Although Rimonabant helped patients lose weight, it also had great negative impacts on the mental health of these patients as a whole, so much that, after reviewing studies, the US Food and Drug Administration refused to approve the drug application from Sanofi-Aventis. The company responded by pulling the application, and eventually Europe came to same conclusion when the European Medicines Agency stated that the risks of the medicine outweighed benefits and advised doctors to refrain from prescribing it. At this point, Sanofi-Aventis halted production entirely, and the incident became a sort of warning sign for the medical community. It was, in a sad and unintentional way, an experiment that yielded a large amount of real-world human data. The message: Don’t turn off the cannabinoid system.
High-THCV cannabis is different from this situation in two big ways. First, in the case of cannabis, THCV is supplied alongside THC and other cannabinoids, not alone, which means that at least some of the cannabinoid system remains active. Secondly, the molecule THCV, despite exhibiting almost identical behavior to Rimonabant, is not Rimonabant. We’ve only identified a handful of studies that evaluate the mental health impact of THCV itself, with mixed results, and we’ve seen no studies that evaluate high-THCV cannabis as a weight-loss solution. That’s not to say it isn’t possible, or that there isn’t some way that appetite suppression is maintained while negative mental effects are counteracted by other components of cannabis. However, we don’t know that.
Additionally, despite numerous reports from the cannabis community to the contrary, research has firmly established that THCV is not independently psychoactive. THCV, like CBD, is thought to attenuate and moderate the effect of THC, which means that together, with THC, THCV can produce a strikingly different experience than THC alone. In other words, THCV does not increase psychoactivity, but it changes the experience of the psychoactive effects already there. Given that THCV is blocking cannabinoid receptors, strains that are high in THCV produce what can be subjectively described as a more clear-headed, racier, more psychedelic high. Users may feel medicated without feeling cloudy. Strains such as Durban Poison and Red Congolese have higher than normal percentages of THCV, although this amount is still usually less than one percent of flower mass. Specialist breeders are currently generating higher yield varieties, so you can be sure that high-THCV products, like high-CBD products, will continue to rise in popularity at dispensaries and rightfully so. THCV varieties provide a different experience and will surely be preferred by many medical cannabis users.
As research continues to unfold, we will keep you updated on the fact-based discussion. However, at this point in time, for this specific area of cannabis, your own personal experiences with medication are likely a better guide than current research. As always, feel free to share this article with friends or write in with your own experiences. We encourage your feedback and enjoy serving as an anchor of reliable information within the medical cannabis community.
R.B. Raffa and S.J. Ward. (2011) “CB1-independent mechanisms of delta-9-THCV, AM251, and SR141716 (rimonabant)”. Journal of Clinical Pharmacy and Therapeutics (2012), 37:260-265.
Cristoforo Silvestri, Debora Paris, Andrea Martella, et. al. (2015) “Two non-psyschoactive cannabinoids reduce intracellular lipid levels and inhibit hepatosteatosis”. Journal of Hepatology (2015).
RG Pertwee. “The diverse CB1 and CB2 receptor pharmacology of three plant cannabinoids: delta-9-tetrahydrocannabinol, cannabidiol, and delta-9-tetrahydrocannabivarin.” British Journal of Pharmacology (2008) 153: 199-215.
Wikipedia contributors. “Rimonabant.” Wikipedia, The Free Encyclopedia. Wikipedia, The Free Encyclopedia, 7 Jan. 2015. Web. 4 May. 2015.