The genetic makeup of an individual cannabis plant — technically both an herb and a vegetable — can feature up to 200 different terpenes. Terpenes are the delicate molecules responsible for the sometimes pungent aroma of weed. All the rage in the burgeoning legal cannabis and hemp industries, terpenes offer much more than merely an enticing tickle of the olfactory sense: They’re the source of significant medicinal efficacy.
Collectively, terpenes offer three major types of efficacy for cannabis consumers and patients, including pain relief (helpful for patients with spasticity and joint pain), a reduction of systemic inflammation (valuable for those with conditions like arthritis, chronic fatigue syndrome, and fibromyalgia), and anti-cancer properties (especially for those undergoing traditional therapies, such as radiation and chemotherapy).
Most research regarding medical cannabis has revolved around cannabinoids, the cousins of terpenes that include cannabidiol (CBD) and the infamous psychoactive molecule that produces euphoria, tetrahydrocannabinol (THC).
The Details of Terpenes
From an evolutionary perspective, terpenes have for millenia served the cannabis plant as protection from pests and predators. For modern lifestyle consumers of this trendy herb, these special molecules offer indulgence into the connoisseur side of cannabis (similar to wine culture).
Unlike the infamous cannabinoid THC, terpenes deliver no psychoactive effect. They do, however, play a critical role in the poorly named entourage effect, a theory of how terpenes and cannabinoids commingle to enhance medical efficacy in humans and mammals.
It is theorized that some terpenes play a role in amplifying or buffering the effects of cannabinoids like THC. One example is myrcene, the most common terpene in cannabis and one that increases the euphoric effects of THC while also delivering a sedative effect.
Many specific terpenes, such as myrcene and pinene, manifest as two similar variants in terms of their molecular structure and medicinal efficacy: Alpha and beta (i.e. α-pinene and β-myrcene). While the alpha and beta types are extremely similar, it should be noted that they feature slightly different bioavailability and efficacy.
Some Major Terpenes
Β-caryophyllene
Beta-caryophyllene (BCP) conveys a scent of black pepper, peppers, spice, and wood. It is unique in that it can be categorized as both a terpene and a cannabinoid. Like other molecules that target CB2 receptors of the human endocannabinoid system, this terpene is effective in the treatment of anxiety and depression. Because BPC features no binding affinity with CB1 receptors, it results in no psychoactive effect like that associated with THC.
BCP is produced by many plants other than cannabis, including black pepper, hops, and rosemary. Cannabis strains rich in BCP include Bubba Kush, DJ Short Blueberry, Girl Scout Cookies, Hash Plant, OG Kush, Pineapple Express, Super Sour Diesel, and Trainwreck.
Myrcene
This particular terpene is present in nearly all strains of the cannabis plant and is typically the most potent (as measured by volume). Also known as β-myrcene, it produces an earthy, musky scent—sometimes accompanied by fruity undertones of clove. Also found in hops, parsley, and wild thyme, myrcene’s major efficacy is a sedative effect (similar to linalool, another major terpene that characterizes indica strains and cultivars).
Myrcene stands out from other terpenes because its volume determines whether a particular example of cannabis is categorized as sativa or indica. Samples containing more than 0.5% myrcene feature a more sedative efficacy and are categorized as indica, while those comprised of less than 0.5% myrcene exhibit lower sedative effects, giving them the energizing and uplifting effect that is typically attributed to a sativa.
Limonene
Another terpene that, like myrcene, determines if a particular strain or cultivar of cannabis exhibits an indica or sativa effect; in this case, the presence of limonene indicates an uplifting sativa. As hinted by its name, limonene is also found in citrus fruits (in the rinds) and is the second most common terpene in cannabis. It is unique in that it aids in the absorption of other terpenes through the skin and mucous membranes. Limonene is also good for those suffering anxiety or depression due to its calming and relaxing effect.
Limonene-rich strains include Durban Poison, Lemon Kush, Lemon Thai, Jack Herer, Jack the Ripper, OG Kush, Sour Diesel, Super Lemon Haze, and Super Silver Haze. Such strains deliver efficacy for those suffering from anxiety, depression, gallstones, heartburn, and even acid reflux. This terpene is an anticonvulsant, has been shown to destroy breast cancer cells in laboratory experiments, and is a powerful antimicrobial.
Linalool
This major terpene features a floral scent similar to spice combined with spring flowers. Like myrcene, it possesses sedative properties of value to those who suffer stress-induced anxiety (100 million Americans are reported to suffer under the burden of social anxiety). From an efficacy perspective, linalool also serves as an analgesic and anti-epileptic, making it valuable for those with conditions such as neuropathy, postoperative pain, Dravet Syndrome, and epilepsy.
Ocimene
This terpene is frequently incorporated into perfumes and colognes due to its appealing aroma. In terms of efficacy, this major terpene possess antifungal, antiseptic, decongestant, and antibacterial properties. Ocimene-rich cannabis strains include Chernobyl, Elwyn, Golden Goat, Lemon Sour Diesel, OG Kush, Space Queen, and Strawberry Cough.
Pinene
The α-pinene variant of this terpene conveys an odor of pine trees and turpentine. Pinene is one of the most common terpenes. For patients, this molecule delivers a systemic anti-inflammatory effect while simultaneously acting as a bronchodilator for those consuming it via inhalation (vaporization or smoking). Pinene, the most common terpene in the plant kingdom, is also found in basil, orange peel, parsley, pine, and rosemary.
Terpineol
This terpene offers aromas composed of floral, herbal, and piney scents. If present in sufficient quantities, it delivers a relaxing effect for many consumers. Like other terpenes and cannabinoids, terpineol offers significant medicinal efficacy for patients and lifestyle users, including acting as an antibacterial, anti-cancer, anti-fungal, antioxidant, and sedative.
Like most terpenes, terpineol is found in plants other than cannabis, including apples, conifers, cumin, lilacs, and even nutmeg. It is most common in cannabis strains such as Agent Orange, Dutch Treat, and Ghost Train.
Terpinolene
This terpene is responsible for many of the floral aromatic aspects to the multitude of strains based on the Jack Herer cannabis variety. Terpinolene has been shown to exhibit antioxidant and anti-cancer effects in rat brain cells. Studies involving mice demonstrate that terpinolene delivers a sedative effect when inhaled.