Before we get to “are they safe?”, let’s talk a little bit about what they are.
Terpenes, and their cousins terpenoids are found in many plants and a few insects. These are naturally
occurring chemicals that vary in many isoprene units linked together. The “C5 rule” implies that the
isoprene unit is typically built by plants in a head to tail fashion. One of the more common terpenes is
called Limonene and here is its structure:
As the name implies, it is found in things that smell “citrusy”. This has 2 isoprene units linked head to
tail and is called a monoterpene. There are other monoterpenes that differ by the placement of oxygen
and extra carbon groups. Each has different odors and flavors.
You may have heard of another terpene called squalene. This occurs in many oils and is a major
constituent of fish liver oils and olive oil. This is known as a triterpene and has 6 isoprene units linked
together in a linear fashion:
This is a precursor for making cholesterol and natural steroids.
There are many more kinds of terpenes with a variety of ringed and linear structures and lengths. The
point is that they naturally occur in plants and insects and some animals. They are used in essential oils
and medicines and are found in wines and many items we consume.
What about CBD and Terpenes?
If you look at the ratio of the various cannabinoids to terpenes in a raw hemp plant, you will see a
certain pattern based on the type of plant and year of growth. In other words, that fingerprint is unique
to the variant of the plant, and that fingerprint also varies depending on the growth season (how much
rain, sun, etc). You’ve experience this in the produce section as you smell one container of strawberries
and compare it to another. Some just smell better!
Just like with other plants, the processing can remove things. Canning fruit makes them smell less fresh,
removes some of the vitamins and minerals and so on. It is the same with CBD oils. The process of
extracting the oil from the hemp plant can alter that initial ratio of cannabinoids to terpenes by changing
the chemical structures or totally destroying some. This is why CBD oil tastes and smells the way it does,
it relates to which terpenes and how much each is still present at the end of the process.
Why do Terpenes matter in CBD products?
Because the natural terpene balance is altered during processing of CBD oil, some companies are adding
them back. In vaping products, terpenes are often added back to the CBD to improve flavor. There are
some CBD tincture products on the market that blend back in specific terpenes to achieve a specific end
target. For example, they add beta-caryophyllene and myrcene to a product intended to help with pain
relief. Myrcene is one of the most prevalent terpenes in hemp plants and accounts for the earthy or
musky smells. It also at high levels (0.5% or more) relates to strains that cause sedative effects. Beta-
caryophyllene, or BCP, has been shown to react with CB2 receptors in term of inflammation and pain
relief. Adding these two back into a product intended to aid with pain makes total sense.
There are even some products now available that offer purified, or synthetic terpenes. These are
intended to enhance other products or help address specific needs. In other cases, strains that are high
in certain terpenes are recommended to address those issues.
How safe are Terpenes?
For the most part, the primary terpenes found in cannabis are on the FDA “generally recognized as safe”
(GRAS) list. Being on this list means that large doses can be consumed without concern for safety. One
caveat to consider is that this list was developed for food and oral products. Vaping/smoking could be a
different category in terms of safety, and without further research it’s hard to make a specific
recommendation.
The terpenes most often associated with hemp are: a-pinene, linalool, BCP, myrcene and limonene.
These are all on the GRAS list. Many cannabinoid companies have produced “flavor wheels” which show
the various terpenes and associated scents and potential effects. If you’d like to check out a specific
terpene, a good place to start is the FDA GRAS list located here. On the left hand side are search tools.
Use the simple search tool and type in the name. You can see if it’s listed and in what capacity if you are
concerned about terpenes or any other chemicals.