This study's goal was to determine how much CBD gets into the bloodstream when full spectrum CBD, broad spectrum CBD, or CBD isolate is administered orally. It was published in the European Journal of Drug Metabolism and Pharmacokinetics in June 2023.
Male and female Sprague Dawley rats were used to simulate human reactions. They used a single dose of 3 different compounds:
- CBD Isolate
- Broad spectrum CBD
- Full spectrum CBD
They also did an in vitro (in the lab, not on rats) test to see whether THC alters the intestinal permeability of CBD.
The bottom line is they found that full spectrum CBD did in fact deliver more CBD to the rats' bloodstream than either the broad spectrum CBD or CBD isolate. They also found that small amounts of THC allowed for better net absorption of CBD.
It is interesting to note the significant differences in improved bioavailability between male and female rats. Based on the same dose, the female rats showed greater improvements with full spectrum CBD than did the male rats.
There was an increase in the oral bioavailability of CBD (12% and 21% in male and female rats, respectively) when administered as a full-spectrum product compared with the isolate and broad-spectrum products.
In vitro permeability assays demonstrated that the presence of THC increases permeability of CBD while also decreasing efflux through the gut wall.
The presence of 0.2% THC increased the oral bioavailability of CBD in male and female rats, indicating that full-spectrum products may produce increased effectiveness of CBD due to a greater exposure available systemically.
The article abstract is here at PubMed.
Berthold EC, Kamble SH, Kanumuri SRR, Kuntz MA, Senetra AS, Chiang YH, McMahon LR, McCurdy CR, Sharma A. Comparative Pharmacokinetics of Commercially Available Cannabidiol Isolate, Broad-Spectrum, and Full-Spectrum Products. Eur J Drug Metab Pharmacokinet. 2023 Jul;48(4):427-435. doi: 10.1007/s13318-023-00839-3. Epub 2023 Jun 19. PMID: 37337087.