Hemp contains over 200 terpenoids, which may enhance the efficacy of cannabinoids. Terpenoids are an aromatic class of phytochemicals, i.e. chemicals naturally produced by plants1. Besides being largely responsible for a plant’s aroma, terpenoids are often able to interact with a range of cell receptors and enzymes, making many of them pharmacologically relevant, particularly at concentrations of over 0.05%. This article will focus on beta-myrcene.
Beta-myrcene is also found in hops (Humulus lupus), which is used in beer and is also in the Cannabaceae family2. It is a monoterpenoid, meaning that its molecular structure has one carbon ring. One way that beta-myrcene may assist in the reported benefits of hemp extracts is through its anti-inflammatory and pain-relieving effects1. In a study on mice, it was found to reduce pain by blocking the effects of prostaglandin-E2, without leading to resistance after repeated injections3. Beta-myrcene was shown to act on the peripheral nerves (e.g. the nerves in your hands and feet), instead of the central nervous system (i.e. the brain); this was the suggested mechanism behind the lack of drug resistance.
Prostaglandins are pro-inflammatory chemicals released by damaged cells4, which intensify the effects of other inflammatory chemicals. This results in increased pain and swelling, two hallmarks of inflammation. The pain-relieving effects of myrcene were found in another study to be blocked by naloxone, a drug used to counteract the effects of morphine5. The authors of this study stated that the results suggest an ability of beta-myrcene to stimulate production of the body’s own opioids, as opposed to reliance on administration of those such as morphine.
In a third study on mice6, beta-myrcene was found to increase the sedative effects of barbiturates, as well as exerting a muscle relaxant effect.
As for humans, beta-myrcene, as part of hops preparations, is recognised as a sedative that can be used to aid sleep in Germany1. Additionally, research showing beta-myrcene’s sedative effect may support the theory that, together with THC, it is responsible for the “couch-lock” phenomenon that can result from recreational use of psychoactive strains.
In addition to these benefits, beta-myrcene may also be able to protect against gastric and duodenal ulcers in higher concentrations7. This appeared to be caused by an increase in the body’s own antioxidant defences. Antioxidants can protect against damage caused by free radicals, which can affect anything from DNA to connective tissue proteins4.
All of these reported benefits may assist in the anti-inflammatory, pain-relieving, sedative and antioxidant effects that the cannabinoids, such as cannabidiol (CBD), may exert. In fact, CBD-rich extracts of hemp have been found to possess more powerful anti-inflammatory effects than CBD alone8. Additionally, a survey of 953 patients9 using medicinal hemp or cannabis preparations also found that overall, the patients were more satisfied with natural, whole-plant products than pharmaceutical products. Only one category, “ease of preparation and intake”, saw higher scores for cannabis-based pharmaceuticals than whole-plant products. As described above, beta-myrcene may be another one of the many “supporting” components of hemp, which not can only unlock the full potential of the cannabinoids, but also exert their own benefits.
4: Tortora, GJ & Derrickson, B, 2012, Principles of Anatomy & Physiology, 13th edn, Wiley.