What Are Terpenes?
Terpenes are hydrocarbons found abundantly in nature which share a chemical precursor with the cannabinoids. They are aromatic compounds which evaporate quickly and produce a vast majority of the smells we associate with foods, perfumes, and other chemicals. Technically, the only real terpene is myrcene, which we’ll talk about shortly. Myrcene is comprised of one molecule of isoprene, which has the chemical formula C5H8. This molecule readily joins with itself to form long chains which are called terpenoids. They serve hundreds of biological purposes and can definitely be considered one of nature’s basic building blocks.
There are some chains of terpenes that contain up to 5000 isoprenes linked together, and these are what make up rubber. Myrcene is also common in mangos, citrus and lemongrass, and it has been found to act synergistically with THC to contribute to the high sensation. Myrcene, along with some other terpenoids, is a positive allosteric modulator of GABA1 receptors in the brain.
English translation: GABA is the primary inhibitory neurotransmitter in the mammalian brain, which means that it is responsible for reducing the excitability of the neurons that cause you to think and act. Myrcene makes the receptor more responsive to GABA, which is the neurotransmitter that activates the GABA1 receptor, and therefore increases its calming effect. It is theorized that this particular terpene contributes to the anti-anxiety properties perceived by being exposed to essential oils, foods, or herbs that contain it.
How do they interact with the body?
The terpenoids found in all three species of Cannabis give it a distinct environmental advantage. The penetrating scent of several terpenes in the trichomes of leaves and flowers repels pests and herbivores, making hemp one of the only plants known that doesn't require chemical growth assistance or remediation. Others have antibiotic and antifungal properties. They produce the pervasive aroma often encountered with Cannabis, but they do many more vital things in the body, under almost everyone’s radar.
One terpenoid, beta-caryophyllene, is found in many strains of Cannabis, and also in oregano and black pepper among other herbs and foods. It is notable as a protector of the stomach lining and also as an anti-inflammatory agent; in addition, it binds with high affinity to the CB2 receptors on T-Cells and Macrophages in the immune system. It is the only terpene known to bind directly to a cannabinoid receptor in the body, and it is one of the reasons that green vegetables in particular are so healthy for the digestive system and overall immune health, as it is found abundantly in many leafy greens.
How do they interact with CBD?
Like CBD, terpenes can act to diminish the high that is perceived when THC is present in the brain. Their subtle psychoactivity throughout a plethora of different brain systems, in addition to their activity in the immune and digestive systems, contributes to the synergistic effect of Cannabis strains or products that contain many compounds rather than just pure CBD or THC.
There are a few specific mechanisms of synergy found between cannabinoids and terpenes: multi-target effects, which means that there are many parts of the brain that are affected by terpenes and cannabinoids alike (CBD is a partial 5-HT1A receptor agonist, the receptor for serotonin which regulates mood); pharmacokinetic effects, like improved bioavailability of cannabinoids and other larger molecules over the blood brain barrier; and by acting as a toxic agent to bacterial and fungal cell walls. To learn the exact science behind the magic of this plant, this study is a great read.