Hemp plants are complex living things made up of countless chemical compounds. While we often focus on the cannabinoids—those compounds unique to the cannabis plant—researchers have been looking into many of the other elements of hemp plants, often with promising results.
Terpenes are one of the most commonly examined compound types. Terpenes are organic compounds found in a wide variety of plants and some insects. You’ve almost certainly come into contact with plants that produce terpenes and ingested fruit or plant matter containing them. They’re so incredibly common you probably don't pay any attention to them, but you should—studies conducted around the world suggest certain terpenes could help with everything from anxiety to protecting cell lining. While research is still in early phases–often only in animal testing–the way terpenes in hemp interact with cannabinoids is of particular interest.
What Are Terpenes and Terpenoids?
Terpenes are a class of hydrocarbons made up of five-carbon isoprene units and are classified by the total number of isoprene units. Classifications include monoterpenes, sesquiterpenes, diterpenes, triterpenes, and tetraterpenes. In other words, terpenes are the building blocks that make a diverse set of naturally occurring compounds in plants and animals.
These compounds are typically odorous and serve diverse functions including defending plants from hungry herbivores—either by creating an odor that wards off plant-eaters or by attracting predators. While these odors repel insects, they have the opposite effect on humans. Terpenes are the primary constituents of essential oils, which are commonly used by perfumers and aromatherapists.
Terpenes are further modified into terpenoids, which are terpenes containing additional functional groups. Terpenoids make up about 60% of known natural products. Many terpenoids have confirmed pharmacological effects and are used in a variety of registered drugs. It’s fairly common to use terpene and terpenoid interchangeably and the distinction isn’t too important for their practical use (unless you're a chemist or other research scientist, in which case it is very important). While most CBD companies put cannabinoids and terpenes/terpenoids in separate categories, cannabinoids are actually terpenoids.
Hemp Terpenes
There are about 200 terpenes and terpenoids that occur in hemp plants, including cannabinoids. These terpenes are what gives hemp its unique odor, color, and flavor. Terpenes also impact the varying effects of different strains of hemp. Like cannabinoids, terpenes are most abundant in hemp flowers. Production of terpenes and terpenoids increases with exposure to light and decreases in less fertile soil.
The terpenes present in a hemp or CBD product vary based on strain. The only way to know which terpenes and terpenoids are present is to look at verified third-party laboratory test results for the product you’re considering.
Here are some of the most common terpenes and terpenoids found in hemp:
Pinene:
Pinene is a bicyclic monoterpenoid. It is a principal monoterpene that reacts with other chemicals to form other terpenes. Two structural isomers are found in nature: alpha-pinene and beta-pinene. Alpha-pinene is the most prevalent terpene found in nature. It is common in citrus fruits, pinewoods, and coniferous plants as well as some animals. It gives off aromas of pine and fir.
Studies support a number of applications for pinene: it has been shown to exhibit antimicrobial properties, limited anticancer use in animal studies, and potential as a possible human anti-inflammatory.
Limonene:
Limonene is monocyclic monoterpenoid formed by pinene. It has a strong citrusy smell like that found in oranges, lemons, and limes. In addition to hemp, it is a major constituent in citrus rinds, rosemary, juniper, peppermint, and pine needle oils.
Limonene is absorbed quickly into the bloodstream, especially when inhaled. It aids in the absorption of other terpenes through the skin and other body tissues. Limonene is of particular interest for researchers: Animal-based studies have found the terpenoid has the potential to cause mammary tumor regression with limited toxicity. Limonene has also been used to dissolve cholesterol-containing gallstones and to relieve heartburn. It has also been the subject of phase 1 clinical trials for patients with breast cancer or colorectal cancer.
Linalool:
Linalool is a monoterpene that is found in many essential oils and is a precursor ingredient in formation of Vitamin E. It is found in lavender, citrus, birch, coriander, and rosewood. Linalool has a floral, spicy, or citrus smell.
Linalool is synergistic with CBD and studies suggest they may have anti-anxiety properties when combined. Researchers have also suggested linalool contributes to the anti-inflammatory effects of some essential oils and could be a potential anti-inflammatory agent on its own.
ß-Caryophyllene:
Beta-caryophyllene is a bicyclic sesquiterpene found in many essential oils including clove, Thai basil, cinnamon leaf, black pepper, oregano, hops, and lavender. It has a peppery, woody, and spicy aroma.
ß-caryophyllene is the only known terpene that directly interacts with the endocannabinoid system. Research has shown this terpene as a natural CB2 receptor agonist. These receptors have been associated with inflammation and neuropathic pain responses. ß-caryophyllene’s interaction with CB2 receptors has led some researchers to state it may be effective in treating chronic, debilitating pain.
Full Spectrum Oils and Terpenes
While these terpenes may be present in the raw hemp flower, they don’t always make their way into CBD tinctures and other manufactured products. This is often by design: CBD isolates are designed to only contain pure CBD. However, if you’re looking for a product that contains linalool or limonene, you’ll need to look for full-spectrum, whole-plant extracts.
Studies have shown that cannabinoids and terpenes benefit from the “entourage effect,” in which the effects of each individual compound are amplified by the presence of other cannabinoids, terpenes, and various phytonutrients. As mentioned earlier, many studies have found certain terpenes and terpenoids are synergistic with cannabinoids including CBD. The presence of terpenes and terpenoids also can also mean compounds are better absorbed by tissues or enter the bloodstream faster, depending on which terpenes are present.
How Do You Know Terpene Content?
Unfortunately, the terpene content of a hemp strain or CBD product is not typically disclosed on the packaging. While you could take a guess at which terpenes and terpenoids are present based on the odor of the product, this isn’t an effective way of determining the chemical makeup of a product and is not recommended.
The only way to get a definitive answer on the terpene content of a particular product is through laboratory testing. Terpene/terpenoid testing isn’t always common, though: many manufacturers only test for cannabinoid content. It may take some time, but if you are looking for a specific set of compounds in a product it is worth your time to check the COA/test results on multiple products before making a purchase from our store. It’s important to remember that not all hemp is of the same strain, grown in the same conditions, or processed in the same way. While one full-spectrum tincture may have the terpenes you’re looking for, others may not.
Some manufacturers enhance their oils and salves with essential oils, whether for taste, aroma, or to add terpenes and terpenoids to their product. While knowing the terpenes present in each essential oil like lavender or clove might give you a general sense of what might be in the CBD product you’re purchasing, only certified lab results will give you a definitive answer on what is in an oil tincture or salve.
Finding the Right CBD Strain
Terpenes and terpenoids have been sought after components in essential oils, cleaning products, perfumes, and traditional medicine practices for years. Knowing the terpenes present in each hemp strain only makes it easier for customers to find a hemp strain that can produce their desired effects.
The Apotheca online store is stocked with hemp flower, CBD tinctures, and salves including full-spectrum whole plant products with rich cannabinoid and terpene profiles. To start browsing for the product that is the perfect fit for you, click here.
This post references the following books throughout:
Cannabis Revealed by Bonni Goldstein, M.D.
CBD: A Patient’s Guide to Medicinal Cannabis by Leonard Leinow & Juliana Birnbaum
