Terpenes are the aromatic metabolites found in the oils of plants. Over 20,000 different kinds of terpenes exist, with at least 200 found in the cannabis plant. Terpenes are produced within plants as an agent to attract pollinators and as defense mechanisms. The term “terpenes” is used interchangeably with terpenoids - terpenoids being the result of the drying or curing process of cannabis. When ingested, certain terpenes bind to the brain’s receptors along with cannabinoids (such as caryophyllene and THC), creating a variety of effects, such as influencing the output of dopamine and serotonin. Other effects detected by scientists include helping with sleep, pain relief, and reduced inflammation. Scientific evidence suggests that terpenes play a lucrative role in boosting and balancing the effects of cannabinoids such as THC and CBD.
While each strain of cannabis has a unique terpene profile, there are 2 that are most abundant. The first is myrcene, which can sometimes account for up to 50% of the plant’s total terpene constitution. With its musky aroma, it is known to be the component responsible for the stereotypical smell of marijuana. The second most common terpene is limonene, which is also found in the peels of citrus fruits. In high concentrations, it can contribute to a citrusy smell to some strains of cannabis. According to Web MD, limonene can be used to promote weight loss, prevent and treat cancer, and treat bronchitis.
Aside from synergizing with cannabinoids like THC and CBD, terpenes affect the body on their own. These include terpenes ability to constrain serotonin usage, boost norepinephrine activity (similar to antidepressants), and have anti-inflammatory properties. As such, terpenes play a key role in full and broad-spectrum CBD oil.
 NCBI Article 1
 NCBI Article 2
 Web MD Article