Terpenes are aromatic compounds produced by nearly all forms of life. In plants, they are responsible for scent and color. Flowers often have the highest terpene content, which is why they have the strongest scent and often the most unique and vibrant colors. Terpenes also act on many different receptors in our body, and because of this, they comprise the active ingredients in most plant essential oils.
What Are Terpenes?
Terpenes are found abundantly in nature, and they are the chemical precursor of all cannabinoids. Terpenes are aromatic compounds, which means they evaporate quickly and therefore produce a vast majority of the smells we associate with foods, perfumes, plants, personal hygiene products, cleaning solutions, and other every-day items.
Myrcene is the simplest terpene, as it’s comprised of one molecule of isoprene. Isoprene has the chemical formula C5H8. Isoprene molecules readily join with one another to form long chains with multiples of 5 carbon atoms – this is the defining feature of all terpenoid compounds. Terpenes/terpenoids serve hundreds of biological purposes and are considered one of nature’s basic building blocks.
There are hundreds of thousands of terpenoid compounds – all compounds that contain a multiple of 5 carbon atoms, such that their chemical formula would include C5, C10, C15, C20, etc.
The terpenes found in the Cannabis species give it a distinct environmental advantage over other plants. Different terpenes are necessary to perform diverse functions, including to: attract insects for pollination; repel pests; protect against fungal and bacterial infection; and even to add protective physical properties, like the flexibility of rubber.
There are some terpenoid compounds that contain up to 5000 isoprene units linked together, like which gives rubber its elastic properties. In addition to cannabis, myrcene is also commonly found in mangos, citrus, and lemongrass, and it has been found to act synergistically with THC to contribute to the sedative effects of cannabis.
In essence, terpenes add to both the flavor and the effects of cannabinoids.
The penetrating scent of 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.
How do terpenes interact with the body?
There are many ways that terpenes interact with the human body. Myrcene, commonly found in cannabis, mangos, citrus, and lemongrass, has been found to act synergistically with THC to contribute to the sedative and anxiolytic effects. This is because myrcene 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 allow you to think and act. Myrcene makes the GABA receptor more responsive to GABA, increasing its calming effect. It is theorized that this particular terpene contributes to the anti-anxiety properties of essential oils, foods, and herbs that contain myrcene.
Another terpenoid, beta-caryophyllene, is found in many strains of Cannabis, as well as in oregano and black pepper, among other herbs. It is notable as a protector of the stomach lining and also as an anti-inflammatory agent. Beta-caryophyllene also 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 cannabinoid receptors in the human body. This property is one of the reasons that green vegetables are so healthy for the digestive system and overall immune health.
Because terpenes are produced by so many living things, most forms of life are responsive to the effects of terpenes. As mentioned above, there are thousands of different terpenes that modify the effects of receptors in our body, and combinations of terpenes will create a unique effect that is slightly different than the sum of the individual effects. This is known as the entourage effect, and cannabinoids as well as terpenes are known to interact with each other to produce specific effects that aren’t possible without that unique combination of terpenoid compounds.
How do they interact with CBD?
The endocannabinoid system (ECS) is one of the most important targets of terpenes in the human body. The ECS mediates the effects of THC as well as some of the effects of CBD. When terpenes are also present and acting upon the ECS, they can slightly alter the effect of CBD or THC on the same system.
Like CBD, terpenes can act to diminish the high that is perceived when THC is present in the brain. Their subtle activity across many different brain regions is responsible for their therapeutic effects on mood, emotion, and cognition. In addition, their activity in the immune and digestive systems as well as the brain contributes to the synergistic effect of Cannabis strains and broad-spectrum products that contain many compounds in addition to pure CBD or THC.
There are a few specific mechanisms of the synergy found between cannabinoids and terpenes:
- Multi-target effects occur because multiple parts of the brain are affected by terpenes and cannabinoids simultaneously (i.e., CBD is a partial agonist (activator) of 5-HT1A serotonin receptors, which regulate mood, as well as a negative modulator of CB1 receptors, which produce the “high” of THC)…together, these reduce the paranoia and anxiety that some users experience with THC use.
- Pharmacokinetic effects include any effect on the levels or movement (kinetics) of CBD through the body. Examples include improved bioavailability of cannabinoids over the blood brain barrier thanks to the presence of certain terpenes.
- Pharmacodynamic effects include the effect of terpenes on the same receptor as CBD. An example is the property of myrcene as a positive allosteric modulator of CB1 receptors, which are negatively modulated by CBD, therefore cancelling out the effects of one another.
Note: this is useful for inhibiting one unwanted effect of CBD without completely removing all of its other effects.