Terpenes are aromatic hydrocarbons, found in the essential oils of every plant and used in healing for thousands of years. Today, terpenes are perhaps best known as the compounds that give each cannabis strain its unique aroma and flavor – but it was only recently that scientists realized terpenes could modify the plant’s effects.
The entourage effect means that cannabis’ active compounds could work more efficiently together than in isolation. Terpenes play a large part in this.
Plants produce terpenes as part of their defenses against pests and disease. They are responsible for the unique smells and tastes of different species. Terpenes also interact with the human body to bring about a variety of changes.
Although many plants produce terpenes, they are especially prevalent in marijuana. In this article, we look at myrcene, the most abundant of all cannabis terpenes.
What Is Myrcene?
yrcene (also known as alpha-myrcene or beta-myrcene) is the most common and a particularly potent terpene, with a spicy, earthy, musky scent that gives cannabis strains a mildly sweet flavor profile.
You’ll also find myrcene in plants like lemongrass, eucalyptus, and ylang-ylang, fruit like mangoes (heard the rumor that they can maximize your high? It’s true), and herbs like thyme, basil, and hops (the one that gives flavor to beer). But myrcene expresses itself most abundantly in cannabis.
Myrcene is the terpene to turn to for calming the body and mind. Research shows that consuming cannabis with myrcene levels above 0.5 percent results in the fondly coined “couch lock,” a deep state of relaxation induced by Indica-dominant strains. In fact, myrcene can make up as much as 50 percent of total terpenes in a cannabis plant. By contrast, sativa-dominant strains usually contain less than 0.5 percent.
The medicinal efficacy of terpenes and benefits triggered in the mammalian endocannabinoid system (ECS) is surprisingly similar to that of cannabinoids. Myrcene’s major effect is sedative in nature, resulting in relaxed muscles and a reduction of pain. This is of obvious value in a number of conditions involving spasticity, seizure activity, or hyperactivity (including Attention-Deficit/Hyperactivity Disorder [ADHD]), and encompasses common and often debilitating diseases like fibromyalgia and Post Traumatic Stress Disorder (PTSD).
According to Russo, the available data and findings “support the hypothesis that myrcene is a prominent sedative terpenoid in cannabis, and—combined with THC—may produce the ‘couch-lock’ phenomenon of certain chemotypes that is alternatively decried or appreciated by recreational cannabis consumers.”
Many doctors and researchers recommend myrcene for patients who suffer insomnia, restlessness, and a multitude of forms of anxiety. According to Leafly, “Pair this famously anti-inflammatory terpene with herbal concoctions containing lemongrass or hops for a powerful calm that may put those numbered sheep to rest.”
Myrcene is also a proven anti-depressant and anti-inflammatory. Like another terpene, limonene, myrcene has an effect on the permeability of cell membranes, meaning it acts as a regulator of other terpenes and cannabinoids, enhancing or buffering their effects and potency (similar to how CBD modulates THC).
This unique capability of myrcene allows it to increase the volume of THC molecules that reaches CB1 receptors in the brain and central nervous system, effectively magnifying the potency of this cannabis molecule’s psychoactive effect—while simultaneously amplifying its medicinal efficacy. In this respect, myrcene is an excellent demonstration of the entourage effect.
“It’s the perfect example of the entourage effect in which both terpenes and cannabinoids work together synergistically to produce or enhance a particular therapeutic effect that could not be obtained from a single cannabinoid or terpene,” wrote author Gooey Rabinski in 2015.
In addition to its sedative effect, myrcene delivers anti-carcinogenic, antimicrobial, antioxidant, and antiseptic benefits. It can also suppress muscle spasms, meaning it shows promise in the treatment of neurological conditions such as dystonia, epilepsy, and Parkinson’s. It is theorized that myrcene’s sedative effect, which can be tranquilizing, might be helpful in the treatment of psychosis.
As well as enhancing THC’s actions in certain marijuana strains, myrcene may have some significant effects of its own. Although research into myrcene, and terpenes in general, is still ongoing, here is what we have discovered so far.
Myrcene is probably best-known for its relaxing, sedative effects. A 2002 study published in the journal Phytomedicine looked at the impact of myrcene on mice. The researchers found that high doses of myrcene made mice less likely to explore the open arms in an elevated plus-maze test. It also increased sleeping time by approximately 160%.
These results may be good news for anyone suffering from stress and insomnia. High-myrcene cannabis strains could potentially offer powerful sedation and help people get a good night’s sleep.
Researchers have also found that myrcene could help to reduce inflammation. Most people associate inflammation with painful conditions such as arthritis. However, scientists have also linked it with various other issues, including heart disease, strokes, diabetes, and cancer.
A 2015 study for the European Journal of Pharmacology looked at myrcene’s effects on inflammation in osteoarthritis. The results showed that myrcene reduced inflammation and catabolic activity in human chondrocytes (cartilage cells). The authors concluded that myrcene could slow down or even halt the progression of cartilage damage in this condition.
Anyone looking to relieve arthritis symptoms with cannabis potentially could consider, therefore, opting for a high myrcene strain. Choose a CBD-rich strain to potentially enhance its effects, as CBD has potent anti-inflammatory properties.
Myrcene may also act as an effective pain-reliever. A 1990 study published in the Journal of Pharmacy and Pharmacology looked at the analgesic effects of myrcene in mice. The authors subjected mice to a hot plate method and the acetic acid-induced writhing test. They observed that myrcene reduced nociception, the pain we associate with physical injury.
Myrcene’s effects were blocked by the drug naloxone, suggesting that this terpene influences the body’s endogenous opioids. These are chemicals which the body produces naturally in response to pain. They act in a similar way to opiates like morphine, but without the dangerous side effects.
Therefore, myrcene may be able to help to relieve some of the most common types of pain. Coupled with its sedative and anti-inflammatory effects, this could make high-myrcene strains helpful for anyone suffering from painful conditions.
Potential Risks: Does Myrcene Cause Cancer?
Although myrcene has a range of potential benefits, some researchers have also linked it with an increased risk of cancer.
A 2010 report for the National Toxicology Program found that high doses of myrcene had carcinogenic (cancer-causing) effects on rats. The study found evidence that male rats, especially, had higher rates of kidney and liver cancer after using myrcene.
Despite these worrying findings, there is currently no evidence that myrcene causes cancer in humans. However, in 2018, the Food and Drug Administration (FDA) removed it from its list of approved additives in light of the research.
There is some dispute regarding whether the government should list myrcene as a carcinogenic substance or not. Until scientists conduct further research, it is impossible to comment with certainty about how safe myrcene is.
However, it is notable that the new FDA regulations apply to synthetic myrcene, not foods that naturally contain it. It’s unknown if the same effects can be caused by naturally-occurring myrcene.
High Myrcene Cannabis Strains
The majority of cannabis strains with a high myrcene content also have indica genetics. This is unsurprising considering that many users choose indicas for their sedating and pain-relieving effects.
Some popular high myrcene marijuana strains include the following:
- OG Kush
- Skywalker OG
- Blue Dream
- 9 Pound Hammer
- Grape Ape
- Granddaddy Purple
- Girl Scout Cookies
- Thin Mint GSC
These strains are potentially useful options for patients with pain, inflammation, or insomnia. Recreational users may also enjoy these strains for their relaxing couch-lock effects. However, since they could increase sedation, they are most suitable for evening use.
Other Sources of Myrcene
As well as cannabis, myrcene is present in various herbs, spices, fruits, and vegetables. Some common sources of myrcene include:
What science says about myrcene
Scientists have been researching myrcene for quite a while, and it is one of the terpenes that gets a lot of attention for its potential medical benefits. In the 1990s, researchers in Brazil found myrcene acted similarly to lemongrass tea, which is used in some folk medicine traditions as a mild sedative. It’s also thought to have some anesthetic qualities, and it’s a key ingredient in the making of the minty-flavoured menthol.
Recent research supports the theory that myrcene has pain-relieving qualities among those suffering from migraines. One 2008 study also found that myrcene, along with linalool and eucalyptol (both are terpenes found in cannabis, though eucalyptol is also commonly called cineol), could help protect human cells from toxins that can cause mutations that lead to cancer.
Myrcene is the most abundant marijuana terpene and has a range of beneficial effects on the body. Studies have shown that it has sedating, relaxing effects and may help relieve inflammation and pain. This means that strains with high myrcene contents could help patients suffering from stress, insomnia, and painful conditions.
Choose an indica or a hybrid strain with strong indica genetics when seeking high myrcene content.
However, it is best to reserve high-myrcene cannabis for later in the day. Otherwise, it may cause extreme sedation to the point where couch-lock occurs.
Some scientists have linked myrcene with cancer in rats. However, there is no evidence that it has these effects in humans. We recommend that concerned individuals read the research and decide whether the benefits outweigh the risks.