Many people believe in the psychoactive or medicinal properties of terpenes, but there is a major issue – cannabis terpene content is rarely consistent.

You walk into a dispensary, open a jar of fresh buds, and deeply inhale the odor. What you are smelling are molecules called terpenes. Not only do they smell nice (and they sure do), but they may have psychoactive and medicinal properties.

Some people believe that terpenes affect the type of high that you have. Will it be relaxed and calm or vibrant and energetic? Whether true or not, it makes for some very cool graphics about different strains.

A section of a PhytoFacts strain profile. From phytofacts.info

As part of my series on the entourage effect, I will be exploring the evidence for several of the claimed effects of terpenes. However, I would like to start with a basic introduction to terpenes and also highlight a major issue – it is very difficult to deliver consistent terpene content in cannabis.

What Are Terpenes & Terpenoids?

Terpenes are a class of organic compounds produced by plants that typically have a strong odor. The strong pine smell from walking in the forest? It’s a terpene called pinene. The smell of citrus fruits? Limonene. The smell of lavender oil? Linalool. You get the idea.

Terpenes are hydrocarbons (meaning they are made up of only hydrogen and carbon molecules). Terpenoids are similar to terpenes, except they contain an additional molecule, such as an oxygen. The terms terpene and terpenoid are often used interchangeably, even though technically they are different. For the sake of simplicity, I will use the term terpene to refer to both classes.

Terpenes are formed from basic building blocks of 5 carbons. Monoterpenes have two of these basic structures (10 carbons) and sesquiterpenes have three of them (15 carbons).

Which Terpenes Are In Cannabis?

Cannabis contains many different terpenes according to one analysis of 11 different strains. They were able to detect a total of 27 different terpenes, including 13 monoterpenoids and 14 sesquiterpenoids. Here is the full list:

  • α-Pinene
  • β-Pinene
  • Myrcene
  • α-Phellandrene
  • Δ3-Carene
  • α-Terpinene
  • β-Phellandrene
  • Limonene
  • cis-Ocimene
  • Terpinolene
  • β-Caryophyllene
  • α-Guaiene
  • Humulene
  • δ-Guaiene
  • Elemene
  • Guaiol
  • γ-Eudesmol
  • β-Eudesmol
  • Agarospirol
  • Bulnesol
  • α-Bisabolol
  • An additional 4 terpenes with an unidentified structure

There are possibly even more terpenes present in other strains. Cannabis testing companies have databases with a much larger number of strains, but their data is not all in the public domain.

How Much of Each Terpene Is In Cannabis?

Looking at the average content of individual terpenes across strains, there is a huge difference between the most abundant and least abundant terpenes. The below plot shows the typical terpene content (as an average of all strains tested):Average terpene content across 11 cannabis strainsThe top 5 most abundant terpenes in the tested strains were myrcene, terpinolene, α-pinene, β-caryophyllene, and limonene. The least abundant terpenes were only present in levels of about 1% of these top ones. So even if you believe a specific terpene has some psychoactive or medicinal quality, you may be consuming very little of it from cannabis.

I should also note that most of these strains were indicas or hybrids more on the indica side. One study saw difference in terpene content between indicas and sativas, although another study did not observe this.

Does Terpene Content Differ Between Cannabis Strains?

Terpene content is all over the place in different strains! Below is the terpene content in different strains for the top 5 most abundant terpenes. You can see how much each individual terpene content differs from strain to strain:

Terpene content of 11 individual cannabis strains

Myrcene (typically the most abundant terpene) is claimed to produce the sedative properties of some cannabis strains. There was nearly a 50-fold difference in the myrcene content between the lowest and highest strains!

Does Terpene Content Differ Within a Cannabis Strain?

At first, it seems that there is a simple solution to the different terpene content between strains. There are cannabis testing companies that measure terpene content. You can look at their information and select a strain that has high abundance of the terpenes you want.

The problem is that there is significant variation from sample to sample within each strain. The actual terpene content is highly dependent on growing, harvesting, drying, and storage conditions. Don’t expect to get the exact same terpene content twice in a row!

The PhytoFacts strain profile (in the image at the beginning of this article) reports only a single value for the terpene content of each strain. On the other hand, Steep Hill Labs reports the terpene content in each strain as a range of values. I believe that this approach more fairly represents to consumers the variability they are likely to encounter.

Image from leafly.com

You can see from this example that the high variability is consistent with that seen in the published study I cite above. Sample to sample terpene content has huge variation, potentially varying by 10-fold or more.

Does Your Method of Consuming Cannabis Affect Terpene Content?

How you consume cannabis will also change the amount of terpenes actually delivered to your body. For example, vaporizing, taking edibles, and tinctures can all deliver different amounts. I will discuss further in an upcoming article.

What To Do About Variability in Terpene Content?

You may think that all of the terpene stuff is bullshit – all you care about is THC. However, if you’ve read this far, you probably do believe that terpenes have some psychoactive or medicinal effect. In this case, you may be asking yourself how to get more of whichever terpene you are interested in. There are 3 options:

  • 1. Pick a strain with a high level of the specific terpene you want. Accept that you won’t really know how much is in there, but hope that it is high enough. Companies like Phylos are working on breeding plants that produce high levels of certain terpenes, although they don’t specific which on their website.
  • 2. Use products with standardized terpene ratios. I’m not even sure whether there are any commercially available yet, but I anticipate the options will increase in the future. For example, ebbu has been isolating terpenes and testing their effects in combination with THC.  Details on their website are still vague, but they have been busy filing patents in this space.
  • 3. Augment your cannabis terpene content with terpenes from other sources. I’ll let you google for yourself, but there are a number of different foods, herbs, or essential oils where you can get the exact same terpenes that are in cannabis. The most famous example is using mango to augment myrcene content, although my analysis showed that this specific strategy is questionable.

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Last modified: July 3, 2017

2 Responses to " Terpene Content in Cannabis – The Variability Problem "

  1. Great piece prof. The variability problem you highlight is inherent to strain name game. If a producer vegetatively propagates a particular variety and grows it in the same controlled condition they will be able to replicate the exact terpene profile of the said variety.

    It would be very interesting to look at how genetically identical clones fare in different environments (geographical location, indoor, outdoor, greenhouse, with/sans inoculation of beneficial microbiota etc).

    Exciting times I tell you. Keep up the amazingly informative posts,

    Cheers,

    Philippe

    • Prof of Pot says:

      Thanks Philippe! It would be very cool to know more about how these environmental factors affect terpene production. Hopefully someone will do this study.

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