A research team led by Johns Hopkins Medicine has discovered further evidence that d-limonene, one of the most abundant terpenes in cannabis, can reduce the anxiety-inducing effects of THC. The findings could further advance the medicinal uses of cannabis as well as reduce recreational use risks for some users.
D-limonene has shown promise in previous rodent studies, however, to date little research has been done to study its effects on humans. In the double-blinded study, published in the Journal of Drug and Alcohol Dependence, 20 healthy adults vaporized d-limonene, THC, THC and d-limonene together, or distilled water. All 20 participants completed 9 outpatient sessions, while 12 participants participated in an additional session and were given THC with a triple dose of d-limonene to analyze the extent of the dose response curve.
During the sessions, researchers measured the subjective effects of the drug including mood, vital signs, and cognitive performance, and compared these against baseline measurements conducted before trials began. The team concluded that combining d-limonene with THC significantly reduced subjective indicators of THC-induced anxiety. Additionally, no interference was observed with THC’s intended effects when administered alongside d-limonene and no effects were observed from d-limonene that differed from those of the placebo test.
“This study is a first step in uncovering how we can mitigate risks of THC when used in medicine, and also is targeted at making cannabis safer for the general, non-therapeutic consumer,” said Tory Spindle, Ph.D., associate professor of psychiatry and behavioral sciences at the Johns Hopkins University School of Medicine.
The researchers intend to continue their research and expand to other terpenes to observe how they interact with each other and THC. The team plans to expand the study to replicate the findings within a larger, more diverse population. Additionally, they intend to analyze d-limonenes effects when the method of administration changes, such as in oral ingestion.