The co-administration of THC and the terpene D-limonene is associated with reduced feelings of anxiety, according to data published in the journal Drug and Alcohol Dependence.
Researchers with John Hopkins University assessed the influence of D-limonene on THC’s subjective effects in 20 healthy volunteers. (D-limonene is a terpene commonly found in many citrus fruits and is among the more abundant terpenes in cannabis.)
Participants who inhaled D-limonene concurrently with THC reported “significantly reduced” feelings of anxiety and paranoia as compared to those who inhaled THC alone. The inhalation of higher quantities of D-limonene was associated with more pronounced effects.
“D-limonene reduced THC-induced anxiety effects in a dose-dependent manner,” the study’s authors reported. Its co-administration did not influence any other effects of THC.
The study’s authors concluded: “D-limonene selectively attenuated THC-induced anxiogenic effects, suggesting this terpenoid could increase the therapeutic index of THC. Future research should determine whether this effect extends to oral dose formulations and evaluate the interactions between other cannabis terpenoids or cannabinoids and THC.”
Research published last year in the journal Biochemical Pharmacology determined that certain terpenes – including borneol, geraniol, limonene, linalool, ocimene, sabinene, and terpineol – modulate THC activity at the CB1 receptor. That study’s authors concluded: “The use of selected terpenes may enable reducing the THC dose in some treatments, and as a result, potentially minimizing the THC-related adverse effects. This would also help in adjusting the treatment to more sensitive populations such as children and elderly. Enrichment with selected terpenes may allow for composition adjustment to personal needs and to changes during chronic use, such as for daytime versus for sleep.”
Full text of the study, “Vaporized D-limonene selectively mitigates the acute anxiogenic effects of delta-9-tetrahydrocannabinol in healthy adults who intermittently use cannabis,” appears in Drug and Alcohol Dependence.