Higher THC Levels Doesn’t Necessarily Mean More Intoxication


A recent study conducted by a team of researchers at the University of Colorado, Boulder, found that smoking higher levels of tetrahydrocannabinol (THC)—such as those found in concentrates—doesn’t always lead to more intoxication. While the results of this study can be helpful for users to get an idea of how much cannabis they should intake, they also provide more argument that the proposed roadside tests for cannabis-induced driving impairment won’t be entirely accurate.

The study observed 121 regular cannabis users and evaluated their cognitive and mobile performances along with blood tests in three separate stages:

  • Prior to cannabis consumption (flower or concentrate)
  • Immediately after cannabis consumption
  • One hour after cannabis consumption

“Surprisingly, we found that potency did not track with intoxication levels,” Cinnamon Bidwell, lead author of the study, notes. “While we saw striking differences in blood levels between the two groups, they were similarly impaired.”

While subjects who consumed cannabis concentrates had noticeably higher blood THC levels – around 1,000 micrograms per milliliter in comparison to the 455 micrograms per milliliter for cannabis flower—they performed relatively the same in the cognitive and balancing tests.

Kent Hutchison, a co-author of the study, emphasizes, “People in the high concentration group were much less compromised than we thought they were going to be. If we gave people that high a concentration of alcohol, it would have been a different story.”

While more research is necessary to truly understand the relationship between THC blood levels and cognitive/balance performances, this study is a clear indication that a roadside THC test will be flawed. The study has hypothesized several reasons as to why this may be.

The most notable is tolerance. Those who smoke concentrated cannabis products tend to have a much better tolerance to THC than those who simply smoke flower. “Another reason,” the researchers discuss in their published paper, “is that cannabinoid receptors may become saturated with THC at higher levels, beyond which there is a diminishing effect of additional THC.”


Please enter your comment!
Please enter your name here

13 − 9 =