Do terpenes in edibles have any effect? How these 5 terps metabolize

Ah, the great entourage theory, or is it more of an ensemble effect? Regardless, terpenes, slightly aromatic and often smelly oils, can alter the effects of cannabis. And the ensemble of ingredients in each strain creates its own unique experience. Little discussed, however, is the fact that some terpenes are only active through olfactory neurons. This means these terpenes may not have the same effects in an edible.

When smoked, THCa converts to active D9-THC. From there it is absorbed into the bloodstream. As many have discovered, active THC (tetrahydrocannabinol) is technically an intoxicating cannabinoid. Contained in the experience of many new consumers is that THC has a different effect when consumed than when inhaled (smoking or vaporizing). For the most part, enzymes in the liver convert D8 or D9 THC to another isomer known as 11-hydroxyl THC.

terpene metabolism

In comparison, research has been slow and has identified some metabolites produced during the digestion of terpenes in humans. Hiroshima University in Japan researched the metabolic conversion of terpenes in rabbits in 1979. (1) The metabolic processes that plants use to produce terpenes were then extensively characterized by 1995. More recently, some of the metabolic by-products produced when humans digest terpenes have also been elucidated. Three terpenes were studied separately by Lukas Schmidt and Thomas Goen, a research couple in Germany. (2)

D-3 fairings

Shmidt and Goen first studied 3-carene (CRN), a minor terpene found in cannabis. While the data for carene were less conclusive, a metabolite was identified. Small amounts of a carboxylated variant of delta-3-CRN known as chimic acid have been found after human digestion. To complement their findings, the researchers noted other possible metabolites that they did not discover.

• Chaminic acid (CRN-10-COOH)

alpha pinene

Alpha-pinene is oxidized in the gut to produce myrtenol, myrtenic acid and two isomers of verbenol. At least the latter may be responsible for some biological effects, according to current research.

• myrtle acid
• myrtenol
• trans and cis verbenol

R-limonene

Limonene is broken down into carvone, but it further converts into some notable compounds during digestion. For example, two isomers of carveol are produced in relatively small amounts by human digestion of r-limonene.

In addition to carveol, more perillic acid than perillyl alcohol is found in human blood (plasma) after consumption of the bitter citrus terpene. According to previous research, the latter fights tumors. However, LMN-8,9-diol is the most common metabolite of r-limonene (LMN) in humans, followed by relatively small amounts of a second isomer.

• LMN-8,9-diol
• LMN-1,2-diol
• perrilic acid
• perillyl alcohol
• trans and cis carveol

Linalool applied to the skin with ice after a burn reduces the likelihood of scarring or blisters. However, when ingested, linalool drastically converts to other terpenes.

Does only the nose know linalool?

Thanks to the terpenes, the nose really knows when it comes to strains you want to smoke, but the effects don’t quite translate to edibles. Receptors in our brain and throughout the body pick up cannabinoids. While different receptors, located for example in the nasal cavity and in the intestine, respond to at least one terpene. – linalool.

Linalool’s anxiolytic properties may not be as pronounced when taken orally as the terpene’s smell. A certain type of receptor is held responsible for this. However, when looking at the bigger picture, a variety of factors alter the effects of linalool depending on the consumption method. First, the effect depends on olfactory neurons, a type receptor (GCPR) present in the nasal cavity, mouth, and gut.

In one study, linalool did not induce GABA-a, which is the same receptor targeted by benzodiazepine drugs, facilitating relaxation. A later study found that linalool induces relaxation through GABA-a, but it depends on olfactory neurons. So, linalool could affect anxiety about edibles if enough of the terpenes can get into the stomach.

Adding to this challenge is metabolism and digestion. Linalool converts into three different terpenes as it passes through the esophagus. In addition, linalool undergoes various changes through metabolism. However, only oxygen atoms (oxygenation) can convert the floral terpene into 8-oxolinalyl acetate; the only metabolite that relieves anxiety through GABA-a. This is promising as linalool could inhibit seizures and epileptic episodes without affecting mood through simple natural processing.

• 8-oxolinalyl acetate
• 8-hydroxylinalool
• 8-carboxylinalool
• Several other hydroxylated, carboxylated and oxygenated metabolites
• geraniol
• Nerol
• a-terpineol

Terpenes are often clear liquid oils; Small things have a big impact.

Myrcene and the monoterpene family

Monoterpenes are a family of molecules and become transient under certain conditions. In fact, beta-myrcene is an important precursor molecule for other terpenes like linalool or citronella. During digestion, myrcene is converted into four different molecules through oxidation, two diols and two hydroxy acids. One diol is known as 10-hydroxylinalool while one of the acids is 10-carboxylinalool.

• 10-hydroxylinalool
• 7-methyl-3-methylene-oct-6-ene-1,2-diol
• 10-carboxylinalool
• 2-Hydroxy-7-methyl-3-methylene-oct-6-enoic acid

Caryophyllene, edible oil and cannabinoid receptors

Linalool and the other three terpenes mentioned above belong to a group of unique molecules made up of ten carbon atoms known as monoterpenes. While sesquiterpenes are made up of 15 carbon atoms; heavier terpenes more commonly found in edibles. This is because lighter monoterpenes evaporate during processing (decarboxylation).

Not only is β-caryophyllene the primary sesquiterpene in cannabis, it also directly activates an acutely therapeutic cannabinoid receptor. When it comes to edibles, the evidence suggests that orally ingested beta-caryophyllene actually tortures the therapeutic cannabinoid receptor.

Do Industries Know How Terpenes Affect Edibles?

Terpenes are having a major impact on a multi-billion dollar industry, driving cannabis forward. Smell and scent drive the cannabis, craft beer and fragrance markets. Because of this, the way terpenes affect various human biological receptors has had far-reaching implications for industries and markets. Producers, processors, and the retail department must all make decisions based on terpene profiles. Of course, the scent of a product is still vitally important, from restaurants to grocery stores to breweries, even when terpenes are less potent when consumed.

Let us know in the comments if you’ve experienced any noticeable effects with terpenes in edibles. And which terpenes would you like to learn more about?

1. Ishida, T., Asakawa, Y., Takemoto, T., & Aratani, T. (1981). Biotransformation of terpenoids in mammals III: Biotransformation of alpha-pinene, beta-pinene, pinane, 3-carene, carane, myrcene and p-cymene in rabbits. Journal of Pharmaceutical Sciences, 70(4), 406-415.
2. one.) Schmidt, L., Belov, VN, & Göen, T. (2015). Metabolism of Δ3-carene in humans and renal excretion of Δ3-carene-10-carboxylic acid (chamic acid) after oral administration. Archives of Toxicology, 89(3), 381-392. b) Schmidt, L., & Göen, T. (2017). Human metabolism of α-pinene and metabolite kinetics after oral administration. Archives of Toxicology, 91(2), 677-687. c) Schmidt, L., & Göen, T. (2017). Human R-limonene metabolism and metabolite kinetics after oral administration. Archives of Toxicology, 91(3), 1175-1185. d) G. Schmidt, L., Lahrz, T., Kraft, M., Göen, T., & Fromme, H. (2015). Monocyclic and bicyclic monoterpenes in the air of German day care centers and human biomonitoring of visiting children, the LUPE 3 study. Environment International, 83, 86–93.
3. Milanos, S., Elsharif, SA, Janzen, D., Büttner, A., & Villmann, C. (2017). Metabolites of linalool and modulation of GABAA receptors. Frontiers of Chemistry, 5, 46.
4. Madyastha, KM, & Srivatsan, V. (1987). Metabolism of beta-myrcene in vivo and in vitro: its effects on rat liver microsomal enzymes. xenobiotics; the fate of foreign compounds in biological systems, 17(5), 539-549. https://doi.org/10.3109/00498258709043961