The ability of certain molecules found in cannabis to enhance and modulate the way consumers experience the effects of THC, CBD, and other cannabinoids has finally graduated from probable to provable.
If that sounds technical, that is no accident. Medical researchers at the University of Tucson in Arizona writing in the journal Nature: Scientific Reports have evidence of the cannabis community’s long-held belief: That terpenes act on receptors found in the body and the brain and profoundly alter the effects of cannabinoids.
The Entourage Effect
It is the first good evidence for the so-called entourage effect, the notion that dozens of naturally occurring compounds in cannabis work together synergistically. How else to explain why three strains of cannabis, each with a THC content of 20% can produce wildly divergent user experiences from energizing or euphoric to mellow and sedating?
Our best guess has always been terpenes, molecules that show up in substantial quantities in chemical analysis of cannabis and which are already known to provide the unique flavours and aromas in high personality strains.
“The pharmacology of cannabis is far more complex than we understand,” says Buck Young, co-founder of Royal City Cannabis Co. “But what we do know is that THC alone is not cannabis and that is a well-supported empirical statement.”
Guelph-based Royal City provides detailed chemical analysis with precise measurements of dozens of terpenes in its roster of small-batch craft cannabis strains, says fellow co-founder Jeff Scanlon. Even their concentrate products are whole-flower and single-strain to ensure that the unique combination of cannabinoids and terpenes are preserved.
master growers Chad Shaddock and Steve Anderson
The timing of that analysis also matters.
“What happens to the flower between the harvest and the jar can have a profound impact on the actual terpene content, these are volatile compounds, and they change from fresh to dried,” says Young. “If the ratios and the absolute content changes, logically that is going to make a difference to the effect.”
The Arizona study suggests their commitment is grounded in fact and not fancy.
According to the study authors “… while terpenes and cannabinoids have been hypothesized to interact to produce an ‘entourage effect,’ the few studies performed to date have shown no interaction. This study is thus the first to show that terpenes and cannabinoids can produce an additive effect when combined.
“This study is also the first to identify the CB1 and A2a receptors as terpene targets and describe the role of these receptors in producing terpene cannabimimetic effects in vivo,” they note.
What that means is that different combinations and doses of at least some of the 500-odd molecules that make up the “bio-pharmacy” of cannabis interact at the receptor level and change the behaviour of their rodent subjects.
Talking to Customers About Terpenes
“Not everybody that comes into the store wants to geek out with a terpene conversation,” notes Jeremy Jacob, co-founder of Vancouver’s Village Bloomery. “But if someone wants to know why a flower with 24% THC doesn’t feel as strong as another that has just 20%, well now we have an opportunity to talk about terpenes.”
“A 20% flower that’s really rich in certain terpenes with a certain terpene profile can be really activating,” explains Jacobs, who is also president of the Association of Canadian Cannabis Retailers. “A big job of terpenes is to catalyze our absorption of THC and in the same act they are modulating the way we feel it.”
Some terpenes are thought to cross the blood-brain barrier, while others can be absorbed trans dermally, through the skin. Alpha-pinene is known to be a bronchial dilator, while myrcene is a known analgesic and sedative. How they interact in different amounts in a complex organism, such as a human being, is the great black box of the entourage conversation.
Legendary cannabis researcher Ethan Russo has presented tantalizing evidence of synergies between THC and CBD and the therapeutic effects of terpenoids for two decades, says Bloomery cannabis educator Luna Vargas. But her mission to pass this information to her clients is frustrated by the reluctance of many cannabis producers to offer detailed chemical analysis of their products to retailers.
Predictably, not everyone experiences any strain the exact same way.
“With hundreds of different compounds interacting with billions of neurons and billions of CB1 and CB2 receptors throughout our nervous system, some people are going to experience it differently,” Young said. “Anecdotally, about 80% to 90% of people will have the same experience with a strain, but then some get the opposite effect.”
Encouraging Experimentation
Boutique cannabis retailers such as Village Bloomery encourage their customers to keep a diary of the strains they try, how it makes them feel, and the time of day, plus other details.
“We have journals at the shop and have these conversations, and if you make note of how a flower makes you feel and you know the terpene profile, you can find what works for you,” Jacob says.
Evidence that the entourage effect is more than urban myth could also reopen the conversation about THC as the sole indicator of flower potency. That obsession has seen moderate THC strains dropped from the non-medical market, and more recently prevented their entry, notes Young.
“Classic strains that have a lot of cachet in the medical market are not present in the legal market for that reason,” he says. “We find a [moderate THC] flower that we love and think it will be off the charts popular, and then it’s not.”
“It’s a toxic ideology,” he describes. “If you went to a bar and people are pounding whisky and someone says, ‘I’d like a light beer’, and you shame them, that’s not a good thing. No one should be forced to consume what for them might be an extreme level of THC.”
“We aren’t creating an accessible marketplace for new consumers,” says Young. “But if we have a 12% strain with a great terpene profile no provincial board will list it.”