What’s the very first thing many cannabis users, beginners and experienced alike, do when they first open a new jar of flower? They smell it. If you’re new to using cannabis flower, maybe it just smells like cannabis to you. But as you become more experienced you’ll likely be able to notice distinct differences in the way the plant smells. Some cultivars are bright and fruity on the nose. Others are woody and earthy. Others still might smell like gasoline.
The reason for that variation comes down to one of the most important categories of chemicals found in cannabis flower: terpenes.
What are cannabis terpenes?
Cannabis terpenes (or “terps,” as you might hear them called) are the fragrant oils produced by the cannabis plant that gives it its distinctive aroma and flavour—they are what, more than anything, distinguishes one cultivar from another. They aren’t the same as THC and CBD, which are cannabinoids. You might instead think of terpenes as the essential oils of cannabis. In dried cannabis, terpenes are found in the trichomes of the bud: those small, hair-like structures that are found on the surface of the buds and leaves of the plant. Typically, the total terpene content of a bud makes up around 1 to 3% of its total weight.
The terpene content and terpene profile (or the amount, and particular variety, of terpenes in a cultivar of cannabis) affect the flower’s flavour, smell, and overall character. The terpene profile, which refers to the unique combination of terpenes in a particular cultivar, is also believed to play an important factor in determining the therapeutic and psychoactive effects of cannabis.
How many terpenes are there?
Estimates on the total number of different terpenes found in cannabis differ, but most sources say that there are somewhere between 100 and 200 different terpenes. A 2019 study by two University of British Columbia researchers found that, in total, more than 150 different terpenes have been scientifically identified in cannabis, but note a lack of research into how terpenes interact with the body.
That’s a lot to keep track of. Thankfully, when it comes to cannabis, we tend to focus mainly on a few key terpenes that you’ll find in many different cultivars—ones that have the biggest impact on how a bud smells and tastes, and the ones you’ll see listed in many licensed stores:
- Myrcene: The most prevalent terpene in cannabis is myrcene, which has an earthy, musky aroma. It’s also found in things like hops, thyme, cloves and bay leaves, and is believed to have a mild sedative influence—many heavy indicas are high in myrcene, for instance.
- Limonene: As you might assume from the name, limonene is a terpene with a citrusy, fruit-like flavour, and is also found in citrus fruits, rosemary and juniper. It tends to be associated with sativas for their anxiolytic effects.
- Pinene: If your cannabis has a strong pine-tree smell, it’s likely rich in pinene, which is one of the dominant terpenes in the classic cultivars Jack Herer and Blue Dream. It’s believed to have strong anti-inflammatory properties, and is also found in common ingredients like basil, rosemary, and—you guessed it—pine needles.
- Linalool: Linalool delivers a floral lavender aroma. If your cannabis has a strong floral smell, that’s likely down to the linalool present. Consistent with its use in the fragrance industry, cultivars with linalool are thought to have a calming effect as well as anti-inflammatory benefits.
- Beta-Caryophyllene: The spicy terpene—beta-caryophyllene has a peppery, spicy aroma. Beta-caryophyllene is also an atypical terpene that, unlike the others, interacts directly with the body’s endocannabinoid system and is believed to have pain-relieving properties since it binds to the same receptors as CBD. It’s also one of the defining terpenes of the famous Cookies family of cultivars, like Girl Scout Cookies, Cookies ’n Cream, and their descendants.
Those are just the five most common cannabis terpenes, and the ones you’re most likely to encounter. Often, cannabis will contain other minor terpenes—including humulene, terpinolene, bisabolol and ocimene, to name a few—that make up your bud’s unique terpene profile.
What’s a terpene profile, and what’s the entourage effect?
It isn’t just one terpene in cannabis that defines it, but the unique combination of terpenes in a particular cultivar, known as its “terpene profile.” Two cultivars may both be high in myrcene, but if one is also high in limonene, it will have a different character than a cultivar that is also high in pinene; the first might taste fruity, while the other might taste like pine.
Increasingly, cannabis growers are getting interested in fine-tuning this terpene profile in their products, as well as attempting to breed and grow plants to maximize the amount of terpenes contained in the flower.
The terpene profile is closely related to the idea of the “entourage effect,” which posits that it is not the THC or CBD content, or even individual terpenes that influence cannabis’ effects, but rather the interaction between the many cannabinoids and terpenes present in the plant that have the most impact on the subjective effects of cannabis. This remains, however, mostly anecdotal, as scientists have not yet found enough evidence to confirm or deny the entourage effect theory.
Therapeutic Effects
Though it is important to remember that terpenes generally occur in fairly low quantities in the cannabis plant, they have gained attention in the medical research world for their potential therapeutic benefits (some of which we mentioned above). Researchers have focused on the potential anti-inflammatory and antioxidant benefits of terpenes and have found that some terpenes, such as beta-caryophyllene and pinene, have the ability to modulate the body’s inflammatory response, reducing the production of pro-inflammatory compounds. This can lead to a reduction in pain and swelling, making these terpenes potentially useful in managing conditions such as arthritis and other inflammatory diseases. Other potential benefits of terpenes include their anti-anxiety effects and their anti-septic benefits.
However, many of the studies of the therapeutic effects of terpenes use them in medical contexts, and there has not been a great deal of research into whether these therapeutic effects extend to cannabis. Overall, much more research is needed to say for sure what terpenes do and do not affect when consumed in cannabis. “Attributes assigned to terpenes in cannabis products, including medicinal properties,” write the University of British Columbia researchers, “remain for now outside of the space of scientific evidence.”