Even as recently as a decade ago, the only things most people knew about marijuana was that it was illegal and it got you high.

Now, not only is some form of cannabis legalized in over half the country, but knowledge of the cannabis plant has become far more mainstream. It's not just THC (Tetrahydrocannabinol -- the main psychoactive element of cannabis), and as more and more people wish to learn more about marijuana for medicinal and recreational use, they've become aware of that.

Cannabinoids like CBD and THC have received the bulk of the press in the wake of legal weed, but another compound that has intrigued people are terpenes. Terpenes aren't just found in cannabis, they're found in other plants as well, and studies have suggested that they may have medicinal benefits, especially in tandem with cannabinoids.

But what are terpenes, what are the most common ones, and how can you use them?

What Are Terpenes?

Terpenes are hydrocarbon compounds found in, among other plants, cannabis. Certain strains are particularly rich in terpenes, and it is where they get their strong aromas. These scents can be distinctly fruity, others may have a strong pine aroma, and others still can have a spicy aroma of pepper. All these and many more are possible.

They tend to be immediately associated with marijuana -- and for good reason: Hundreds of terpene compounds have been found in cannabis. But they're found in other plants, as well, and the aroma serves as a surprising defense mechanism in nature. To protect itself from herbivores in the wild, terpenes can attract carnivorous predators to drive the herbivores away.

Terpenes have become a popular part of the marijuana conversation, as legal usage becomes more widespread. Growers seek to prioritize terpenes in their strains to enhance the flavor and scent, helping with both the taste and marketing of the product.

Terpenes vs. Terpenoids

Terpenes and terpenoids are sometimes used interchangeably, but there are some differences between the two. Whereas terpenes are hydrocarbons, terpenoids contain more oxygen functionality.

Entourage Effect: How Do Terpenes Impact Cannabis?

Research about what terpenes can do for users of cannabis is still limited, to an extent; marijuana is still illegal on a federal level, making it hard for researchers to study it. What research is available, though, suggests a lot of promising effects.

"A lot of what the research out there is showing is that CBD on its own tends to be less effective than CBD in conjunction with smaller amounts of THC and other cannabinoids, and the terpenes that you find in cannabinoids," said Kris Krane, president of medical cannabis brand development and advising company 4Front Ventures. "It's the entourage effect of the different cannabinoids and terpenes that tends to be most effective."

That "entourage effect," as it is generally known, refers to terpenes reacting synergistically with cannabinoid compounds like THC in the endocannabinoid system (neurotransmitters and cannabinoid receptors found in most mammals' nervous systems) in order to affect the body and mind.

Though research is limited, the supposed effects outlined in studies like Dr. Ethan B. Russo's in 2011 could have major impacts on both physical and mental health, thanks to the entourage effect. A recent 2017 study from Konkuk University in Seoul, South Korea looked at terpenes from the forest and found an association between certain terpenes in plants and different biological reactions.

Should a terpene have physical effects, the effect will depend on the specific terpene. Terpenes with similar aromas may have similar effects. Overall, terpenes may be able to provide physical effects that include:

  • Anti-inflammatory properties
  • Pain relief
  • Antibacterial properties
  • Antifungal properties
  • Assistance with muscle spasms

In addition, other terpenes may be able to help with the mental impact of issues such as:

  • Depression
  • Anxiety
  • Insomnia
  • Stress

Terpenes Commonly Found in Marijuana

Of course, what terpenes a new cannabis user is looking for will depend on what they're seeking a possible treatment for. An individual terpene compound is not a one-stop relief shop.

There are, as mentioned, hundreds of different terpenes that can be found in marijuana. Here are some of the more notable and commonly-found terpenes in cannabis, what their aroma is, and what effects they may have.

Myrcene

Myrcene is one of the terpenes frequently found in cannabis. Its aroma is distinct, herbal and citrusy in nature -- which is fitting, as it can also be found in fruits like mango. Dr. Russo's study, in noticing myrcene's incredibly sedating effect and making note of studies that showed it as a potential muscle relaxant in mice, said that by working in entourage with THC it "may produce the 'couch-lock' phenomenon of certain chemotypes that is alternatively decried or appreciated by recreational cannabis consumers."

In addition to sedative properties, myrcene is said to be an effective anti-inflammatory, as well as an analgesic. Perhaps most interestingly, the Konkuk University research suggested that the myrcene they studied from a Korean forest showed potential to be cytotoxic to certain tumor cell lines.

Linalool

Linalool can be found in certain cannabis strains, but it is also a naturally occurring terpene often found in lavender. Its strong aroma is floral but has an unmistakable spice to it as well. Often used in essential oils for aromatherapy purposes, linalool, like myrcene, is said to have sedative properties.

One standout effect studies have suggested linalool could have is its ability to help with convulsions in seizures. Medical marijuana's use in reducing seizures has been a major driver of legalization.

Linalool's relaxing properties are also said to spread to being therapeutic in treatments of depression and anxiety, as well as stress.

Pinene

Pinene, true to its name, gives off a pine aroma -- and it can be found in pine needles and conifer trees. Like myrcene, studies have suggested that it has great potential as an anti-inflammatory. Dr. Russo's study also noted evidence that it could provide relief as a bronchodilator, helping conditions like asthma.

What was also noticed about pinene was that, as an acetylcholinesterase inhibitor, it exhibited the ability to help with memory, as well. Russo suggested it may work as a way to counteract short-term memory loss from too much THC.

At Konkuk University, they found a correlation between pinene use and preventing tumor cells from metastasizing. Certain pinene compounds were also seen as having potential in a chemotherapeutic sense, showing cytotoxic tendencies against cancer cells.

Limonene

With an aggressively citrusy aroma, evoking lemon in particular, it's no surprise that in addition to cannabis, limonene can be found in citrus fruits -- helping provide that scent. It's incredibly abundant in nature, and even if cannabis research is limited, there has been research on citrus oils to suggest there are positive properties in it.

One of limonene's purported abilities is to assist with depression and anxiety, and the fragrance given off is associated with an elevated mood. Antioxidant properties in limonene is said to help with inflammation in the lungs. Researchers have also found that limonene can cause apoptosis in cancer cells and can help prevent them from proliferating.

Humulene

Humulene gives off an especially earthy aroma, and can be found in hops; perhaps you've experienced the humulene taste in the flavor of beer, before. Also known as α-caryophyllene, humulene is another example of a terpene that has been studied in possible tumor and cancer treatments, showing potential as an active component in an essential oil to both prevent tumor growth and metastasis.

Research is especially limited on this, but humulene has also been said to be an appetite suppressant -- not the kind of effect you would typically associate with marijuana. It is seen as having anti-inflammatory and antibacterial properties, as well.

Caryophyllene

Also referred to as β-caryophyllene, this terpene shares some characteristics with humulene. That's because humulene is actually an isomer of caryophyllene. Caryophyllene's aroma is similarly woody, but with far more of a spice than humulene. It can also be found in black pepper.

Caryophyllene has shown anti-inflammatory properties, and one study even suggested that it played a role in reducing alcohol intake in mice. It was also, in the past, used to help treat duodenal ulcers.

Borneol

Borneol, with its distinct minty aroma, has been used in traditional medicine before. It is yet another terpene that can act as an anti-inflammatory, particularly for lung inflammation and neuropathic pain. It is also effective at repelling insects.

Terpineol

Terpineol's floral aroma is especially reminiscent of lilacs, and it can often be found in perfumes. Studies on terpineol tend to note its strong sedative effects. Combined with the scent, it's not unusual for terpineol to be implemented in aromatherapy.

Terpene Products

So if terpenes supposedly work so well with CBD and THC to create these helpful effects, how can an interested person with a medical marijuana card, or who lives where marijuana is legalized, take advantage of them?

Should you purchase legal weed products, check the label. Some oils and concentrates, among other products, have started listing the terpenes that can be found, as well as percentages. That percentage can come in handy; knowing your product has higher-than-usual concentrations of a sedating terpene can prepare you for the effects.

Say you receive legal cannabis in the form of the flower itself. Here, you can let your sense of smell lead the way. Knowing what certain terpenes smell like, if your product gives off a similar aroma, you can get a sense of what effects it could possibly have.

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