What are Terpenes? Read Our Complete Guide To These Incredible Molecules
Cannabis is a pharmacopeia wrapped up in a plant. With a dominant and intoxicating scent, the flower demands our attention. As it turns out, the molecules responsible for the herb’s striking aroma may do a lot more than provide a pleasant fragrance. These molecules, known as terpenes, work in tandem with other cannabis compounds, including the molecule that causes the famous marijuana “high.”
Together, the concert of chemicals cannabis strains produces trigger a phenomenon known as the entourage effect. Simply stated, all of the compounds in cannabis work together to produce unique and strain-dependent experiences. Confused? No worries—here’s everything you need to know about cannabis terpenes and what they do.
What are Terpenes?
Terpenes are responsible for the amazing aromas that many plants produce—including cannabis. When a wine sommelier puts their nose to a glass or when someone first takes in the aroma of a freshly ground bud, they are enjoying the fragrance of terpenes.
Terpenes are aroma molecules produced by all plants, making up the bulk of active constituents found in essential oils. In fact, terpenes are the among largest and most diverse families of organic compounds on earth.
In cannabis, these vibrant molecules are manufactured in the nearly microscopic resinous trichomes of the plant. Trichomes are the sticky, oil-producing glands that give marijuana flowers their crystal-laden appearance. These resin glands are also home to the famous psychoactive tetrahydrocannabinol (THC).
While terpenes provide aroma, molecules like THC, called cannabinoids, do not produce any scent. THC alone isn’t what makes cannabis plants unique. Terpenes account for about 10 to 20 percent of the weight volume of resin in cannabis flowers.
More than 20,000 varieties of terpenes appear throughout nature, about 200 of which are found in cannabis. In contrast, the herb can produce an estimated 111 unique cannabinoids. These numerous molecules can be combined in a multitude of ways to produce plants with unique chemical properties.
In a way, these numerous combinations give each cannabis strain and flower its individual personality.
What Do Terpenes Do?
Wondering why your favorite OG Kush smells so different from the Banana Candy flower you picked up last week? Terpenes provide nuance to cannabis strains, offering an aromatic subtlety that differentiates one plant from another. The molecules work in tandem with cannabinoids like THC, providing each individual strain with a distinct chemical fingerprint.
Current theory speculates that it is this unique blending of terpene aroma molecules and the other active constituents that give each cannabis cultivar its individual effect. For example, OG Kush produces different ratios and types of terpenes and cannabinoids than Banana Candy. These chemical differences mean that each flower will not only have a distinct aroma, but both strains may even produce different physiological effects when consumed.
The distinctions between cannabis varieties can even present themselves on the genetic level. Thanks to revelations in genetic sequencing, researchers have found that individual cannabis cultivars are much more sophisticated than you might think.
In fact, a 2017 study published in PLOS ONE found that 30 different genes are responsible for terpene production in marijuana. These numerous genetic markers are expected to give cannabis a similar aromatic complexity to wine, which is famous for its robust array of flavors and fragrances.
What Do Cannabis Terpenes Do for the Plant?
Understanding terpenes is essential to understanding how cannabis strains differ from one another. However, these aroma molecules do a lot more than simply please the nose. As it turns out, the compounds are key to the cannabis plant’s survival. Exactly what these molecules do for the herb, however, is surprising.
Terpenes are compounds that give plants the ability to respond intelligently to their environment. Humans and animals react to their environment through movement. When we are frightened, we run away. When we want something, we used movement to go and get it.
Plants, however, have a different way of relating to the world. Plants can’t exactly move around to get what they want. Instead, they use chemical signaling to either attract what they want or push things away. One of the ways plants attract or repel is through scent. The exciting fragrance produced by some terpenes is what attracts pollinators, calling beneficial insects to the plant to ensure the herb’s survival.
Apparently, strong aromas work their magic on humans, too. The intoxicating scent of cannabis, for example, is so enticing that herb lovers around the world are drawn to its complex and distinct aroma. Humans have cultivated this smelly flower for centuries, giving it the ability to thrive.
Yet, terpenes aren’t all fun and games. These mysterious molecules have a dark side. Cannabis flowers may not be able to run away from their predators, but they’re certainly not defenseless.
Akin to an external immune system, the herb produces some types of terpenes both to ward off predatory insects and protect against infection. Bitter terpenes that deter herbivores like deer and rabbits are typically found in low-hanging branches and leaves. Flowers, on the other hand, tend to produce sweeter terpenes to attract pollinators.
Just like a mother passes along characteristics to her child, the ability to produce specific terpenes can be passed along from parent to seedling. For example, if a mother plant was attacked by a certain pest early in its life, it’s offspring may be more likely to produce certain terpenes as a result.
A truly responsive chemical system, pants also release different terpenes as a real-time reaction to what is going on around them. If a nearby plant is attacked by insects, that plant can release certain aromatic compounds as a distress signal. Neighboring plants can detect this signal and will begin to produce their own terpenes to protect themselves from attack.
Benefits of Terpenes
As it turns out, the same reason terpene molecules are beneficial for plants may also make them beneficial to human health. Many terpene molecules express anti-microbial and antiseptic properties. More still are powerful antioxidants, protecting cells in the human body from stress-related damage. This makes sense, considering that some of these same compounds may protect plants from the sun’s ultraviolet radiation.
Amazingly, terpenes are proving themselves to have as much medical value as cannabinoids such as THC and cannabidiol (CBD). The latter is a cannabis compound that has proven to reduce seizures in patients with severe forms of epilepsy.
For example, a study conducted in 2011 at Northeast Forestry University in China revealed that one common terpene, pinene, helps in the treatment of some bacterial and viral infections. Limonene, another common terpene, has exhibited both anti-inflammatory and anti-cancer characteristics in early research. It has also been shown to help sufferers of depression and to aid in digestion.
Wondering why the benefits of terpenes are so vast? Well, apparently, humans smell with their whole body.
Terpenes’ Effect on the Human Body
Our first interaction with terpenes comes through the nose and respiratory system. As we inhale, terpenes travel up the nose and trigger olfactory nerves, which relay signals directly to the processing center of the brain. Yet, the nose isn’t the only organ that responds to these molecules. In fact, there is a growing collection of evidence which suggests that aroma molecules themselves may actually trigger unique environmental responses in the human body.
The same olfactory receptors that allow you to enjoy the robust aroma of cannabis are also found throughout bodily tissues. Receptors that may respond to plant terpenes have been found in the skin, lungs, heart, kidneys, and, perhaps most shockingly, sperm.
One study published in Frontiers in Physiology, for example, found that fragrance molecules in bananas and apricot successfully dilated blood vessels in the lungs. The terpenes produced a strong enough reaction to counter the effects of inflammation that is typically seen in asthma patients.
For another example, walking through a forest, where sharp-scented pine terpenes fill the air, has been shown to improve immune function and reduce stress on the nervous system.
The verdict is in, then: terpenes do a lot more for the human body than simply provide a pleasing scent. In fact, as little as a 0.05 percent terpene concentration in a plant is considered pharmacologically significant. This means that even trace amount of these phytochemicals may have profound benefits on human health.
Understanding that terpenes can have a profound effect on the human body provides even more reason for the wide-ranging medicinal benefits that the cannabis plant has to offer. Not only does the plant contain a particularly powerful class of chemicals called cannabinoids, but the herb is a terpene-producing powerhouse.
Most Common Terpenes in Cannabis
There are over 200 known terpenes found in cannabis. Each plant strain tends to have unique terpene compositions; hence different strains have different smells, tastes, and effects. Some terpenes, however, are more common than others. Here’s a brief list of the most common aroma molecules found in marijuana plants.
Beta-Caryophyllene (BCP) is one of the most common terpenes in the cannabis plant. In fact, a derivative of this terpene is what drug-sniffing dogs are trained to smell when looking for marijuana. The punchy molecule, however, isn’t exclusive to the psychoactive herb. This spicy compound is more commonly found in black pepper, giving a sweet and sharp kick to the household spice.
There is more to BCP than spiciness, however. The molecule may actually act as a cannabinoid, similar to THC. Before you get too excited, however, don’t expect a psychoactive high from this molecule. Instead, the fragrance engages cannabinoid receptors on immune cells. Cannabinoid receptors are the landing sites for molecules like THC.
Now, however, BCP seems to engage these landing sites as well. As a result, the aromatic compound is expected to reduce inflammation. Some preclinical studies also indicate that BCP may even have an effect on anxiety and depression.
Myrcene is a musky terpene commonly found in lemongrass and hops. This calming molecule, however, is also found in the cannabis plant. Common in heavy-handed Indica strains like Hindu Kush, myrcene is expected to have hypnotic and muscle-relaxant properties. In fact, the experts at Steep Hill Labs, a California-based cannabis testing facility, suggest that the presence of this molecule is what differentiates Indica and Sativa strains.
In popular culture, Indica strains are often touted as possessing sedative and physically relaxing effects. According to Steep Hill, this could be because Indica flowers tend to produce more than 0.5 percent myrcene. The higher the myrcene content in a strain, the more sedative it is likely to be. This may be beneficial for medical cannabis consumers seeking relief from muscle tension and insomnia.
Most commonly found in the lavender plant, linalool is a sweet and floral terpene with a calming attitude. In fact, linalool is so relaxed that it has proven to be as effective at relieving stress as common prescription anti-anxiety medications in clinical trials. In other early experiments, the molecule demonstrated anti-inflammatory and pain-fighting properties.
Some cannabis cultivars, like Lavender, Granddaddy Purple, and Alaskan Thunder Fuck contain high levels of Linalool. Unlike strains with high levels of myrcene, however, linalool is not tranquilizing. While the aroma produces a calming effect, it likely will not cause you to feel overly sedated.
Bright and uplifting, limonene is a terpene commonly found in citrus fruits. In cannabis, expect to find this cheerful aroma in strains like Lemon Skunk, OG Kush, and Super Sour Diesel. In scientific literature, limonene has shown impressive therapeutic value. Not only does the terpene have anti-inflammatory properties, but the molecule has shown potential against cancer cells. In addition, the compound may have an anti-depressant quality as well.
Humulene is the culprit behind the bitter, woody notes in beer. While common in strains like Chemdawg and Girl Scout Cookies Thin Mints, this molecule is most abundant in hops and sage plants. Don’t let this molecule’s recreational reputation fool you, however. Humulene holds some serious medicinal potential.
Research has shown that this terpene can reduce inflammation and may even treat pain. When combined with cannabinoids like THC and CBD, these therapeutic compounds might be amplified. Regardless, expect a calm and uplifting vibe from humulene-dominant strains.
There are few things more relaxing than the scent of pine needles and evergreen forest. As the name suggests, pinene is a terpene with a sharp, pine aroma. This terpene is one of the most abundant in the world, meaning that many humans interact with this molecule on a daily basis.
Pinene is the opposite of myrcene in terms of energy. While many cannabis terpenes are on the sedative side, this one is all get-up-and-go. Focused, uplifting, and calm, pinene has a knack for inspiring concentration and lifting spirits. Strains like Jack Herer, Blue Dream, and Trainwreck all contain substantial amounts of pinene.
The molecule may help consumers breathe a little easier. Studies show that pinene has bronchodilatory effects, potentially reducing constriction in lung tissue. According to a 2011 review published in the British Journal of Pharmacology, the terpene may also combat some of the memory-impairing effects of psychoactive THC
Terpinolene is one cool cat. The molecule provides a light and aromatic sweetness to strains like Jack Herer. Perhaps slightly woody in nature, it is more commonly found in apples and pine trees. Relaxing, this is sedative in nature. Well, at least that’s what early rodent trials suggest. Interestingly, the strains that test highest in this sleepy molecule tend to be Sativa flowers with an energetic reputation. Yet, as many Herbivores know, even the most energetic strains can still be mellow and lighthearted. Experimental medical research suggests that this molecule may have anti-cancer properties.
Most often found in lilac, terpineol is a laidback and focused terpene often found in easygoing strains like Skywalker OG and White Widow. Like many other terpenes on this list, this sweet-scented molecule may have cancer-preventive properties. For example, one 2010 study found that the herb showed an anti-tumor effect in lung cancer. Further research still suggests that the relaxing aroma may relieve pain and inflammation, another common theme among cannabis terpenes.
There is a reason why a cup of chamomile tea is calming. The chamomile flower is rich in a terpene called bisabolol. This mellow and easygoing terpene offers a fresh, floral aroma. In cannabis, this sleepy molecule is often found in strains like Master Kush, Rockstar, and ACDC.
While not as tranquilizing as myrcene, strains high in bisabolol may be helpful for those who struggle to get to sleep. The calming nature of this terpene also seems soothing for bodily tissues. A 2009 review from the Journal of the American Chemists’ Society presents early evidence that the molecule successfully eases inflammation, has antibiotic potential, and may even have anticancer properties as well.
Sweet with a touch of umami and citrus, this intriguing terpene is an inflammation-fighting powerhouse. Often found in strains in the Haze family, including Super Silver Haze, this terpene has a slow and sedative vibe. While strains in the Haze family are often classified as Sativas, varieties with particularly high levels of delta-3 carene are perhaps best for those hoping to ease into a relaxed state of mind. In scientific literature, this molecule is expected to have a beneficial impact on bone repair after injury.
With a balsamic-like aroma, borneol is a rare and fascinating terpene. Plant extracts with high levels of this compound have been used in Chinese medicine for at least a thousand years. Like many plant compounds, borneol has demonstrated anti-cancer potential in the laboratory.
Traditionally, the extract was used to treat coughs, pain, and digestive distress. Some of these properties are supported by modern science, which has found that borneol has analgesic properties and may relax blood vessels in the lungs, aiding the respiratory system. Amnesia Haze and other Sativa cultivars are more likely to contain higher levels of borneol than other cannabis varieties.
Also known as eucalyptol, this terpene has a spicy mint aroma. One of the most commonly used essential oils, cineole is expected to improve memory, attention, and cognitive performance. The molecule also has a potent effect on the lungs, opening airways and reducing inflammation. The terpene is most abundant in rosemary, but come cannabis strains also express high levels of this energizing molecule. Find cineole in Headband and related strains.
Source: HERB co