As explained in a previous article in this series, terpenes are fragrant essential oils that not only give each cannabis cultivar its unique smell and taste, but also interact with other compounds in order to enhance the psychoactive and medical properties of a strain – a phenomenon known as the entourage effect. Myrcene is the most abundant cannabis terpene, and regularly makes up twenty percent or more of a plant’s overall terpene profile.
Also found in hops as well as fruits like mangoes, myrcene adds a peppery tone to cannabis cultivars like White Widow, OG Kush and Grandaddy Purple. It is generally considered to have a sedative effect and is occasionally cited as the main cause of the ‘couch lock’ that cannabis users sometimes experience, although these claims require a little investigation.
Does Myrcene Cause Couch Lock?
Myrcene has been used as a sedative in folk medicine for many years, with plants like lemongrass and hops – both of which contain this terpene – often taken as muscle relaxants and sleeping aids[i]. In one study, high doses of myrcene caused mice to increase their sleep time by about 250 percent, yet there’s very little research as to whether or not myrcene in cannabis produces a similar effect[ii].
Nevertheless, it is often claimed that the tranquilizing nature of Indica varieties is caused by high myrcene levels, with lower concentrations of the terpene contributing to the energizing properties of Sativa types. According to some sources, all Indica strains contain more than 0.5 percent myrcene, while all Sativas contain less than this amount. Whether or not this is true is the subject of some debate, however, as others claim that myrcene can be found in roughly equal amounts in Sativa, Indica and hybrid varieties.
Therefore, while there is some evidence that myrcene is capable of acting as a sedative, to say that it is responsible for couch lock in cannabis users may be a little presumptuous, and more data is needed in order to clarify this point.
The Benefits Of Myrcene
Aside from its relaxing properties, myrcene also offers a number of medical benefits. For instance, it has been found to alter liver enzymes in order to combat toxins which can produce mutations within our DNA. According to more than one study, by blocking an enzyme called CYP2B1, myrcene prevents a common toxin called aflatoxin from damaging DNA and causing cancer[iii].
Separate research has found that myrcene helps to kill tumour cells, with efficacy seen against breast carcinoma, colon adenocarcinoma and gall tumours[iv]. On top of that, the terpene prevents inflammation in chondrocytes, which are the main cells found in cartilage, leading to suggestions that it may prove to be an effective treatment for osteoarthritis[v].
Finally, myrcene has displayed significant analgesic effects in animal studies, reducing pain responses in mice and other rodents. Importantly, though, the terpene acts via a different mechanism to most pharmaceutical painkillers, exerting peripheral rather than central effects. As a consequence, no tolerance build-up was seen in any of the animals involved in the study, even after multiple administrations[vi]. Based on this finding, the study authors conclude that myrcene warrants further investigation as a safe, non-addictive alternative to opioids and other problematic painkillers.
[i] Russo EB. Taming THC: potential cannabis synergy and phytocannabinoid‐terpenoid entourage effects. British journal of pharmacology. 2011 Aug;163(7):1344-64. – https://bpspubs.onlinelibrary.wiley.com/doi/full/10.1111/j.1476-5381.2011.01238.x
[ii] Do Vale TG, Furtado EC, Santos Jr JG, Viana GS. Central effects of citral, myrcene and limonene, constituents of essential oil chemotypes from Lippia alba (Mill.) NE Brown. Phytomedicine. 2002 Jan 1;9(8):709-14. – https://www.sciencedirect.com/science/article/abs/pii/S0944711304701786
[iii] De-Oliveira AC, Ribeiro-Pinto LF, Paumgartten FJ. In vitro inhibition of CYP2B1 monooxygenase by β-myrcene and other monoterpenoid compounds. Toxicology letters. 1997 Jun 16;92(1):39-46. – https://www.sciencedirect.com/science/article/abs/pii/S0378427497000349
[iv] Sobral MV, Xavier AL, Lima TC, de Sousa DP. Antitumor activity of monoterpenes found in essential oils. The Scientific World Journal. 2014 Oct;2014. – https://www.hindawi.com/journals/tswj/2014/953451/
[v] Rufino AT, Ribeiro M, Sousa C, Judas F, Salgueiro L, Cavaleiro C, Mendes AF. Evaluation of the anti-inflammatory, anti-catabolic and pro-anabolic effects of E-caryophyllene, myrcene and limonene in a cell model of osteoarthritis. European journal of pharmacology. 2015 Mar 5;750:141-50. – https://www.sciencedirect.com/science/article/abs/pii/S0014299915000412
[vi] Lorenzetti BB, Souza GE, Sarti SJ, Santos Filho D, Ferreira SH. Myrcene mimics the peripheral analgesic activity of lemongrass tea. Journal of Ethnopharmacology. 1991 Aug 1;34(1):43-8. – https://www.sciencedirect.com/science/article/abs/pii/037887419190187I