The entourage effect is the standard explanation for why different strains produce different highs. In 2010, Dr. Ethan Russo published a study proposing phytocannabinoid-terpenoid synergy. He believed that terpenes intercede the effects of THC and CBD on the body. This hypothesis quickly took hold in the cannabis community. The experience of Indica strains vs Sativa strains was attributed to the different terpene profiles.
Leafly, the prominent cannabis strain resource, spent a great deal of time and money to redesign their website. Rather than leaning on genetics, terpenes were the focus of their education. “Because Indicas and Sativas can have specific physical traits, it has led to the assumption that each also has certain effects, but this is insufficient,” Russo said.
“Regardless of whether a strain is an Indica or Sativa, its chemical profile—that is, the cannabinoids and terpenes in it—will determine how it affects you, not its physical features.” Thanks to recent findings, it’s possible that terpenoids from cannabis do not mediate an entourage effect by effecting cannabinoid receptors.
What The Study Showed
It is important to note that the 2010 publication that started the terpene mediated entourage effect hypothesis was an opinion piece. The author was simply proposing a possible explanation. He even makes suggestions on studies that would investigate his hypotheses. The cannabis community and cannabis resources like Leafly simply ran with an idea that was not scientifically proven.
The study that resulted, “Terpenoids From Cannabis Do Not Mediate an Entourage Effect by Acting at Cannabinoid Receptors” came from a university in New Zealand. Researchers created a study to determine if terpenes in the plant had detectible receptor-mediated activity.
Furthermore, to study if terpenes could modify the activity of delta 9 THC cannabidiol, or CB1 or CB2 receptors. The study found no data produced to support the hypothesis that any of the five terpenes tested (alone or mixed) interact with CB1 or CB2. The study showed that the binding of delta 9 THC or CBD was in no way altered by the presence of terpenes. This strongly questions the terpene mediated entourage effect.
How The Study Was Executed
To study receptor activity, scientists perform Radioligand Binding Assays. In laymen’s terms, a molecule that binds to a receptor is tagged. The tagged molecule is then exposed to the receptors. The amount of molecules bound to the receptors is then measured. Often, this measurement is collected electromagnetically or fluorescence detection.
Researchers tagged delta 9 THC and CBD molecules and then exposed them to CB1 and CB2 receptors to measure base line binding. They then mixed these tagged cannabinoids with terpenes individually and terpene mixtures. Researchers chose to study the effects of Myrcene, ɑ-Pinene 𝛃-Pinene, 𝛃-Caryophyllene, and Limonene. They found that none of these terpenes individually, and no mixtures, significantly changed the binding affinity of THC or CBD.
What This Means For You
Recently it has become more accepted that THC percentage is not the only indicator of how “high” a product will make you. Now, we need to move away from the hypothesis that terpenes impact your high. Instead, consider that not all of the cannabinoids playing a role in your high have been identified. The recent discovery of the extremely potent THCP and CBDP supports this. Studies have shown that whole plant extracts are more effective at pain relief than THC or CBD isolates. It is possible that the cannabinoids not tested or reported on the strain label are potentially responsible for mediating your high.
When you purchase extract products, consider looking for broad or full spectrum extracts. CBD products, for example, are more beneficial when they are whole plant-derived full-spectrum products. When purchasing a cartridge, the higher testing distillate cartridge might not get you higher than the full spectrum CO2 one.
More research needs to be done on the effects of lesser-known cannabinoids, molecules that do bind to CB1 and CB2. Since terpenes might not fully interact with CB1 and CB2, they cannot be considered cannabinoids. Cannabinoids are defined as naturally occurring and biologically active. Terpenes are not biologically active.
This means that the labeling standards in Washington State that include terpenes in the “total cannabinoids” should be reconsidered. Now more than ever it is clear that we need to support cannabinoid research so we can understand both the psychoactive and therapeutic properties of cannabis compounds.