CBD to THC conversion in the gastrointestinal tract – debunking myths

CBD to THC conversion in the gastrointestinal tract – debunking myths

Cannabis and Cannabinoid Research published a paper in response to a biased article sponsored by the pharmaceutical company Zynerba Pharmaceuticals, Inc., a manufacturer of synthetic gel spreads containing synthetic CBD. The article commented on in the said paper suggested that in the stomach CBD is transformed into THC (1). The eponymous stance of “Even High Doses of Oral Cannabidiol Do Not Cause THC-Like Effects in Humans: Comment on Merrick et al.” article (2) was very well backed with research, debunking the myth particularly disturbing for parents of children with epilepsy which is treated with relatively high doses of CBD. The parents’ fears are in fact justified as if CBD-THC conversion actually did take place on a large scale they might be worried about such a mechanism’s consequences in the future.

To back their stance, the authors cite numerous studies that involved doses ranging from several hundred milligrammes up to more than 1 gramme of CBD per day. None of these studies reported any reaction typical for THC. Moreover, several of those studies have also examined the blood for the presence of both THC and its metabolites, detecting none of them. The question arises, then: where did the CBD-THC conversion hypothesis come from in the first place?

Technically speaking, from the chemical point of view such a transformation is actually possible, but what can happen under extreme and very specific conditions in a laboratory is rarely possible in real life. Unfortunately, it can be suspected that the authors of the controversial article (as is often the case they actually work for the pharmaceutical company, which itself is not a bad thing) have been given the task of proving a thesis that should concern patients taking oral CBD oils and thus increase their employer’s income. Let’s not tackle the moral issues here, but the scandalously biased way the research was conducted together with a very subjective selection of experiments makes any scientific conclusion drawn from them controversial, to say the least.

First off, the fact that CBD is practically insoluble neither in water nor in gastric juice (that is to say in a solution of hydrochloric acid) has been completely ignored. Instead, the authors of the article have simply dissolved the CBD in methanol. The second problem is that even after being dissolved in alcohol in order to be added to water or gastric juice CBD would quickly precipitate back to its solid form. What’s more, in the study, sodium dodecyl sulphate was added to the solution. Sodium dodecyl sulphate is simply speaking a plain soap. Having a snack composed of soap flushed down with methanol is not necessarily the most common way of administrating CBD, is it? This is what I meant by putting in question that the author’s qualifications. Although towards the end of the article one can see, that the authors might have been experiencing some qualms as they at least admitted that the processes in the glass may not be resembling those observed in a living organism, they do not hold back to conclude their paper with an arbitrarily statement that some part of the CBD in the stomach will transform into THC, a claim not backed with any actual evidence.

You may have the impression that these pseudoscientists are capable of proving any given thesis. Fortunately, there are also those who do not tolerate such blatant manipulation and debunk myths for the benefit of patients – Grotenhermen, Russo and Zuardiauthors, the authors of “Even High Doses of Oral Cannabidiol Do Not Cause THC-Like Effects in Humans…” are among the most respected names in the field.
Now to address the question posed in this short piece’s title: there is NO SUCH THING as CBD to THC conversion in the organism!

Jarosław Szulfer PhD

1. J, Merrick, et al. Identification of psychoactive degradants of cannabidiol in simulated gastric and physiological fluid. Cannabis Cannabinoid Res. 1.1, 2016, pp. 102-112.
2. F, Grotenhermen, E, Russo and AW, Zuardi. Even High Doses of Oral Cannabidiol Do Not Cause THC-Like Effects in Humans: Comment on Merrick et al. Cannabis and Cannabinoid Research. 2.1, 2017.