By Dr. Daniela Vergara
Terpenes are natural compounds that give plants their smell, including cannabis. Recently, people have become more interested in their possible health benefits. Terpenes don’t just affect how cannabis smells; they might also change how it makes you feel.
This post will introduce you to the fascinating world of terpenes.
Cannabis sativa and Its Many Compounds
One special thing about Cannabis sativa is that it produces many different compounds. These can be divided into two main groups:
- Primary compounds: These are essential for the plant to grow and survive, like fibers that give it structure or sugars that provide energy.
- Secondary compounds: These are not necessary for survival but can help protect the plant [1, 2]. Terpenes belong to this group.
What Do Terpenes Do?
The C. sativa plant makes many compounds, and some of these are called terpenes, which are responsible for the smell [3, 4]. There are many terpenes, but in marijuana-type C. sativa, three terpenes are very common: beta-myrcene, beta-caryophyllene, and limonene [5].
What Other Compounds Does Cannabis Produce?
Besides terpenes, cannabis also produces cannabinoids and we talked about these in a previous post (link). These compounds interact with the body’s endocannabinoid system. While some other plants also produce cannabinoids [6, 7], they are not the same as the ones in cannabis[8].
What Are Cannabis Terpenes?
Terpenes are organic compounds made from five-carbon molecules called isoprene. There are over 30,000 types of terpenes in nature [9-11]. In plants, they can:
- Attract pollinators
- Help spread seeds
- Protect against insects and competing plants
Types of Terpenes
Terpenes are classified by the number of carbon atoms they have [12]:
- Monoterpenes (10 carbons) – Example: limonene and beta-myrcene
- Sesquiterpenes (15 carbons) – Example: beta-caryophyllene
- Diterpenes (20 carbons)
Terpenes Are Found in Many Unrelated Plants
One of the most fascinating things about terpenes in C. sativa is that they are also found in many other plants, both closely and distantly related. For example, hops—the main ingredient in beer and the closest living relative of C. sativa—also produce alpha-humulene. These two plants share a common ancestor from about 25-28 million years ago [13]. However, pines, which produce alpha- and beta-pinene, share an ancestor with C. sativa from around 250 million years ago! Even though pines and C. sativa are only distantly related, they still produce some of the same compounds. And once again, what makes C. sativa so remarkable is that it produces all these terpenes—and more!
Terpenes in Marijuana… and Other Plants!
You might be surprised to learn that many plants share the same terpenes as cannabis:
- Beta-myrcene – Found in mangoes
- Beta-caryophyllene – Found in black pepper
- Limonene – Found in lemons
- Alpha and beta-pinene – Found in pine trees
- Linalool – Found in lavender
- Alpha-humulene – Found in hops
Cannabis Terpenes: A Wide Variety of Compounds
One of the most interesting things about C. sativa is that it produces a wide range of terpenes. Different strains have different amounts and types of terpenes [5], which may affect their smell and possibly their effects .
Can Terpenes Help Classify Cannabis Strains?
The terpenes in cannabis are responsible for the scents of different strains, like Lemon Skunk or Super Lemon Haze, and may be useful to group strains [5, 14-17]. Some suggest that terpenes may be a better way to group cannabis strains than the usual labels like “sativa” or “indica” [5].
How Are Cannabinoids and Terpenes Measured?
To analyze cannabis, scientists use chromatography, a technique that separates compounds and you can read more about it in our previous post (link):
- Gas Chromatography (GC) – Measures terpenes but changes the structure of cannabinoids.
- High-Performance Liquid Chromatography (HPLC) – Measures both acidic and neutral forms of cannabinoids without altering them.
Similarities Between Terpenes and Cannabinoids
At one point during their production, terpenes and cannabinoids come from the same chemical pathway and start with the same basic compounds (precursor molecules). Some suggest that terpene and cannabinoid genes work together in a network [18], influencing the final chemical makeup of the plant. Some terpenes may even interact with the endocannabinoid system [19, 20], just like cannabinoids do.
This growing knowledge of terpenes suggests that they might play a bigger role in cannabis effects than we once thought—making them just as important as cannabinoids in therapeutic use.
Possible Therapeutic Uses of Terpenes
Many terpenes may have health benefits, including anti-inflammatory, anticancer, antiseptic, astringent, and digestive properties [11]. For example, humulene appears to have anti-inflammatory and pain-relieving effects [21, 22]. Linalool also seems to have anti-inflammatory and antimicrobial properties [23], and it may even help with depression [24]. This is one of the reasons why linalool is commonly used in yoga classes. When we clean our homes, we often use products containing alpha- and beta-pinene because of their antimicrobial properties [25].
Questions About Terpenes
One big question I have about terpenes is why Cannabis sativa produces so many of these compounds. In other words, what is their ecological purpose? Some scientists believe that the plant makes terpenes to protect itself from UV radiation, while others think they help defend against herbivores [26, 27].
A recent preliminary study found that when cannabis is grown outdoors, it produces a greater amount of terpenes [28]. This might be because outdoor plants face more challenges like temperature changes, sunlight exposure, hail, diseases, and insects. Since outdoor plants must defend themselves from these threats, it makes sense that they might produce more terpenes compared to indoor plants, which grow in stable conditions with controlled light, nutrients, and temperature.
These are just some of the questions that could be answered through experiments. I hope you enjoyed this short overview of cannabis terpenes!
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