CBD Conversion to THC

As previously stated, CBD and THC have the same chemical formula and their structures are very similar. When CBD is consumed orally and metabolized, does it get converted to THC? Will individuals who consume large amounts of CBD experience a THC “high” because the CBD gets converted into THC?

Interestingly, at least two different in vitro studies used simulated gastric fluid and showed that there is some evidence that CBD can be converted to THC. However, the results of these in vitro studies may not be applicable to humans who consume CBD orally, because simulated gastric fluid does not provide the same exact physiological conditions that exist in a human stomach. (WHO 39, p 11)

When testing humans undergoing CBD treatment, spontaneous conversion of CBD to THC has not been demonstrated. As an example, in a 6 week study in which Huntington’s disease patients were given high doses of oral CBD (700mg/day), the average CBD plasma concentration range was 5.9-11.2 ng/ml, while no delta-9-THC was detected.(WHO 39, p 11) Also, a summary of other studies examining the effects of high dose CBD did not show that the patients experienced THC-like effects, and some studies actually showed that the patients experienced effects opposite to those of THC. (Grotenhermen) Furthermore, in a study in which 120 healthy human subjects were given an oral solution containing CBD 300 mg, THC was not detected in plasma after administration of the CBD, and the study participants did not exhibit the psychomimetic effects typical of THC. (Crippa)

References

• World Health Organization (WHO) – Expert Committee on Drug Dependence Thirty-ninth Meeting Cannabidiol (CBD) Pre-Review Report Agenda Item 5.2 Geneva, 6-10 November 2017
• Grotenhermen F, Russo E,  Zuardi AW. Even High Doses of Oral Cannabidol Do Not Cause THC-Like Effects in Humans: Comment on Merrick et al. in Cannabis and Cannabinoid Research. 2016;1(1):102–112; DOI: 10.1089/can.2015.0004. Cannabis and Cannabinoid Research. 2017; 2(1): 1-4.
• Crippa JA, Zuardi AW, Hallak, JE, et al. Oral Cannabidiol does not convert to delta 8 or delta 9 THC in humans: a pharmacokinetic study in healthy subjects. Cannabis and Cannabinoid Research. Published Online: 4 Oct 2019; https://doi.org/10.1089/can.2019.0024 Accessed October 2020