Terpenes, or isoprenoids, provide cannabis with its unique bouquet. The molecules are quite small and consist of repeating units of a compound called isoprene. Although less well-known than the major cannabinoids, terpenes are instrumental to the physiological and psychoactive effects of cannabis. The relationship between terpenes and cannabinoids, known as the "entourage effect," ultimately differentiates one strain of cannabis from another.
Terpenes play a vital role in the plant kingdom; they deter insect predation, protect plants from environmental stresses, and act as building blocks for more complex molecules, such as cannabinoids. Many terpenes act synergistically with other varieties of terpenes, and some either catalyze or inhibit formation of different compounds within a plant. Understanding how terpenes function allows scientists to manipulate cannabinoids to desired ratios.
Primary terpenes found in cannabis are the following:
α Pinene accounts for cannabis' familiar odor, often associated with pine trees and turpentine, α Pinene is the most common naturally occurring terpenoid and acts as both an anti-inflammatory and a bronchodilator.
Linalool has a floral scent reminiscent of spring flowers, but with spicy overtones. It possesses sedative properties and is an effective anxiety and stress reliever. It has also been used as an analgesic and anti-epileptic.
Myrcene is the most prevalent terpene and is found in most varieties of cannabis. Myrcene concentration dictates whether a strain will have an indica or sativa effect. Strains containing over 0.5% of myrcene produce a more sedative high, while strains containing less than 0.5% myrcene have an energizing effect. Myrcene is also present in thyme, hops, lemongrass, and citrus, and is used in aromatherapy.
Limonene is a dominant terpene in strains with a pronounced sativa effect. It is also found in the rinds of citrus fruits. Limonene aids in the absorption of other terpenes through the skin and mucous membranes, and has been used to treat anxiety and depression.
Ocimene is frequently used in perfumes for its pleasant odor. In nature, this terpene contributes to a plant's defenses and possess antifungal properties.
Terpinolene has been shown to exhibit antioxidant and anticancer effects in rat brain cells. Studies with mice show that terpinolene has a sedative effect when inhaled. In addition, terpinolene is responsible for many of the floral notes found in Jack Herer varieties.
Terpineol is known for its pleasant smell and is often used in soaps and perfumes. It is known to have relaxing effects.
Valencene is present in Valencia oranges and contributes to cannabis' citrus aroma.
β Caryophyllene is the only terpene known to interact with the body's endocannabinoid system (CB2). It produces anti-inflammatory and analgesic effects.
Also present in geraniums, geraniol emits a rosey scent that makes it a popular perfume additive. It is an effective mosquito repellent and shows a potential protective effect against neuropathy.
α Humulene contributes to the "hoppy" aroma of cannabis. This terpene acts as an appetite suppressant and exhibits potent anti-inflammatory activity.