Photo by: Gina Coleman/WeedmapsImage lightbox
Limonene is a terpene recognizable for its zesty citrus fragrance, primarily in lemon, but also in orange, lime, and grapefruit. Limonene is found in the peels of these citrus fruits and in many varieties of cannabis. Along with myrcene, limonene is one of the most abundant terpenes to occur in cannabis. The terpene has also been explored for its many and varied potential medical uses, including its anti-inflammatory, anti-anxiety, antibacterial, and anticancer qualities.
What is limonene?
In addition to its prominent presence in many varieties of cannabis, limonene occurs naturally in mint, juniper, rosemary, pine, and fennel. Some of these sources, such as rosemary, are channeled in essential oil form for therapeutic purposes including scalp massage and in muscle balms. For industrial purposes, limonene has diverse uses: as an organic herbicide, a solvent to remove oil from machinery, and a paint stripper. In traditional medicine, the terpene has been tapped for centuries as a component of remedies for bronchitis, heartburn and gallstones. Modern medicine is now delving into the therapeutic possibilities of limonene and many other terpenes, such as caryophyllene.
What is limonene good for?
In addition to its prominent presence in many varieties of cannabis, limonene occurs naturally in mint, juniper, rosemary, pine, and fennel. Some of these sources, such as rosemary, are channeled in essential oils for therapeutic purposes including scalp and muscle massage. Limonene also has diverse industrial uses: as an organic herbicide, a solvent to remove oil from machinery, and a paint stripper. In traditional medicine, the terpene has been tapped for centuries as a component of remedies for bronchitis, heartburn, and gallstones. Modern medicine is now delving into the therapeutic possibilities of limonene and many other terpenes, such as pinene.
What does limonene smell like?
You have probably gotten a whiff of limonene if you have scrubbed your home with any lemon or citrus-scented cleaning products. In fact, indigenous populations have taken advantage of limonene's reported antimicrobial properties for centuries. On the dining table, you have experienced limonene when sinking your teeth into a citrus fruit or when indulging in a sweet treat such as chocolate-covered orange peels. Fruity beverages such as lemonade and citrus-flavored ice cream are two other culinary interactions you may have had with limonene.
Is limonene good for skin?
The terpene is a popular ingredient in cosmetics, fragrances, and body creams. However, in high concentrations, limonene is considered to be a skin irritant that could trigger contact dermatitis for those with an allergy to the terpene, according to 2014 research published in the journal Contact Dermatitis.
Therapeutic properties of limonene
Limonene, one of the most well-studied terpenes found in cannabis, has a variety of possible effects on the immune system. The terpene's antibacterial and antimicrobial effects are being researched, in addition to its potential to combat mood disorders and cancer, among other ailments.
Anti-anxiety
Essential oils that contain limonene are widely used by humans in hopes of treating conditions such as anxiety and insomnia. To validate these uses, a 2013 study published in BMC Complementary and Alternative Medicine examined the ability of limonene to reduce symptoms of depression and anxiety in rodent models of these disorders. Although the researchers found no evidence for the antidepressive effects of limonene, it seemed to improve anxiety-like states by interacting with the brain's serotonin system.
Antioxidant and anti-inflammatory
Using an animal model of ulcerative colitis, a 2017 study published in the journal Molecular Medicine Reports demonstrated limonene's apparent ability to reduce disease activity and organ damage. These effects were due in part to the terpene's antioxidant and anti-inflammatory properties, which have been reported by other researchers as well, including a 2015 study published in the journal Food and Chemical Toxicology.
Analgesic
The anti-inflammatory and antioxidant properties of limonene may partially explain why it seems to reduce pain in animal models, as reported in a 2017 study published in the journal Neuroscience.
Anticancer
Limonene has demonstrated prospective anticancer properties in many studies, including one published in 2018 in New Zealand journal OncoTargets and Therapy. Researchers experimented on the lung cancer cells of mice and found that limonene inhibited the growth of the cells while suppressing the proliferation of transplanted tumors.
Another study, conducted on cancer cells in a lab and published in 2009 in the Indian Journal of Carcinogenesis, determined that limonene could enhance the effects of chemotherapy drugs being used to treat certain types of prostate cancer. In addition, a 2012 study published in the journal Life Sciences demonstrated that as part of a blood orange oil emulsion, limonene could kill human colon cancer cells in a lab setting. The study went on to assert that this particular emulsion could even offer hope for the prevention of cancer. While these findings are optimistic, clinical trials examining limonene's efficacy in treating humans suffering from cancer are still needed.
Does limonene get you high?
Tetrahydrocannabinol or THC is the component in cannabis that gets you classically high, but limonene has exhibited potential mood-altering effects, especially with regard to anxiety and depression. So, while limonene may not be directly responsible for a cannabis high, the terpene may still impact how you feel.
Role of limonene in cannabis
There are numerous cannabis strains with high levels of limonene:
- Lemon G
- Emerald Jack
- Cookies and Cream
- Shining Silver Haze
- Liberty Haze
While you may detect a lemon scent and flavor in some limonene-rich cannabis strains, you may also perceive a non-specific citrus quality. Some cannabis varieties with limonene possess other potent citrus aromas and tastes, such as tangerine, so your experience will not be the same across the board.
Bottom line
Among the most common terpenes found in cannabis, limonene is notable for its aromatic, flavorful citrus profile and potential as an anti-inflammatory and anticancer agent.
Major contributions from Dr. Adie Rae.