High-THC cannabis concentrates boost levels of THC in the blood more than smoking cannabis flower, but they don’t necessarily produce a stronger “high,” a new study says.
The use of concentrates produced significantly higher levels of THC in blood plasma, the study found, yet participants who consumed cannabis flower and those who consumed cannabis concentrates “showed similar neurobehavioral patterns after acute cannabis use.” A range of short-term measures of impairment did not change with the strength of the cannabis consumed.
The researchers surmise that may be because concentrate users have greater tolerance to the effects of THC, or that “cannabinoid receptors may become saturated with THC” when consumed at higher levels.
The study, published in JAMA Psychiatry, surveyed 121 users of cannabis flower and concentrate who were randomly instructed to purchase and consume higher and lower THC products.
The study included 55 flower users and 66 concentrate users between 21 and 70, who had used cannabis four times in the past month, did not use tobacco on a daily basis, and had prior use of concentrates with no adverse reaction, among other criteria.
Buy 3 grams and come back in 5 days
The flower test subjects were instructed to purchase 3 grams of either a 16% THC strain or a 24% THC strain, while the concentrate participants were randomized to purchase 1 gram of either 70% or 90% THC concentrate.
Federal regulations in the United States prohibit researchers from providing any cannabis to research subjects that isn’t produced by a single farm at the University of Mississippi, which many researchers have criticized as being “junk, ill-suited for clinical trials,” with levels of THC far below that which is readily
available in the legal — and illegal — cannabis market. Some researchers have chosen to sidestep that rule by instructing participants to purchase their own cannabis from legal dispensaries.
Between the baseline assessment and the experimental session, the participants were given a five-day period to “familiarize themselves with their study cannabis.” On the day of the experiment, the participants used the cannabis at their home with their preferred method of use, and then were assessed in a mobile laboratory dispatched to check their short-term intoxication.
The relationship between potency and impairment
The study looked to answer three main questions: how short term use of cannabis flower and concentrate is associated with THC plasma levels, subjective intoxication and mood, cognitive performance and balance, if these associations differ between flower and concentrate users, and if these associations differ in relation to THC potency.
Cannabis intoxication was measured using the 12-item Addiction Research Center Inventory-marijuana effects scale, as well as according to a three-item cannabis intoxication scale that rated three sensations: mentally stoned, physically stoned, and feeling high. They were also asked to complete four cognitive tasks, including three separate memory related tasks and a “quiet standing balance” test.
The concentrate users “reported more frequent current concentrate use and exhibited greater blood levels of THC and metabolites at baseline.” Nonetheless, “despite this higher THC exposure, concentrate users did not show greater short-term subjective, cognitive, or balance impairment,” according to the researchers.
The researchers in the current study said that part of their motivation was to assess the potential negative effects of THC on the brain, and that “the existing literature is limited by the use of low-THC products and drug administration approaches that do not reflect legal market cannabis use.”
They also said that the “much higher” THC exposure in concentrate users is reason for concern about the “long-term clinical and neurohabavioral implications of concentrate use.”