Updated: Feb 5
A 2015 study entitled "The Conversion and Transfer of Cannabinoids from Cannabis to Smoke Stream in Cigarettes" that was published in the journal Natural Products Chemistry & Research investigated the characteristics and underlying biochemical mechanisms involved when patients and consumers smoke (combust) the herb.
The study noted that "the primary route of administration for both medicinal and recreational use of cannabis is inhalation of the volatiles formed upon combustion or vaporization."
Acidic Precursor Explainer
Cannabinoids such as CBD (cannabidiol) and THC (tetrahydrocannabinol) manifest in several different forms (called analogs). The psychoactive version of THC and the primary type of CBD are known as the neutral or active versions.
"Neutral versions of cannabinoids are produced by acidic precursors that molecularly morph under the proper environmental conditions, including UV light, exposure to oxygen, or heat."
Neutral versions of cannabinoids are produced by acidic precursors that molecularly morph under the proper environmental conditions, including UV light, oxidation (exposure to oxygen), or the heat from vaporization or combustion (smoking). In the case of the cannabinoids in question, CBD is derived from CBDA and THC's source is THCA.
Thus, the study measured the amount of the precursors CBDA and THCA that, when combusted for smoking, converted to their neutral versions, CBD and THC, respectively.
Recovery of THC in the smoke stream varied from 27.5 to 46.3 percent, with an average of 37 percent. "The recovery of CBD showed similar results, with a range of 30-43 percent and an average of 38 percent."
Recovery of THC in the smoke stream varied from 28 to 46 percent, with an average of 37 percent. The recovery of CBD showed similar results, with a range of 30-43 percent and an average of 38 percent."
The study's authors noted that the recovery rates in smoke of both CBD and THC were nearly identical and that there "was no statistically significant difference between the CBD and THC recoveries."
On average over all experiments, nine (9) percent of the THC was recovered from the side stream smoke of the joint (smoke that is lost to the environment and not inhaled) while six (6) percent was present in the ashes. In the case of CBD, 11 percent was recovered from the side stream smoke and four (4) percent from the ash.
View the original study.