Terpenes are categorized based on the number of isoprene units in the molecule. They are composed of groups of isomers which are defined by a shared chemical formula, but have atom arranged in a different way to give rise to different chemical properties. Monoterpenes have an empirical formula of C10H16, sesquiterpenes have the formula of C15H24, and diterpenes have the formula of C20H32.
Terpenoids are a class of compounds that are derived from terpenes but have additional functional groups, usually oxygen containing functional groups, in addition to their basic hydrocarbon structure. Similar to terpenes, terpenoids are also sometimes classified by the number of carbon atoms in the structure. Monoterpenoids have 10 carbons, seqsuiterpenoids have 15 carbons, diterpenoids contain 20 carbons, etc. Terpenoids are frequently and incorrectly referred to as terpenes although this is only a minor error in semantics and it is generally acceptible to lump them all together as “terpenes”. Occassionally, you’ll hear slang of them refered to as “the terps” which is a surprisingly more accurate description.
Terpenes are found throughout nature, such as fruit and a variety of plants, including cannabis. They are aromatic compounds that contribute to smell and flavor. There are also potential medical benefits of terpenes. However, the medical benefits of terpenes are not completely scientifically understood. There are peer reviewed papers that use a rat or a mouse model to reach weak conclusions. More conclusive data would need scientific, peer reviewed studies involving humans, which would be difficult due to the nature of cannabis being federally illegal.
A few of the most common terpenes / terpenoids are listed below:
β-myrcene – Myrcene is one of the most of abundant terpenes found in cannabis. Myrcene is common to a lot of other plants. Lemmongrass, hops, and mangos have myrcene. It has potential sedative properpies and research says that it may reduce seizure activity. Research also shows that it potentiates barbiturate sleep time. A similar synergistic activity with THC might also exist.
β-Caryophyllene – β‐Caryophyllene is typically the most common sesquiterpenoid observed in cannabis. Due to monoterpenes being more volatiles and sesquiterpenes being “heavier” β‐Caryophyllene can sometimes be the most prominent terpene if the cannabis has been processed under heat or isn’t as fresh since the lighter terpenes are the first to come off. It is purported to have anti-inflammatory effects based on mouse studies.
Linalool – Linalool is a monoterpenoid alcohol that is most often compared to the smell of lavender. It has been purported to have anxiolytic and sedative effects.
Limonene – Limonene is arguably the second most common terpenoid in nature. It is common to lemons and other citrus fruits.
Pinene – Pinene is a monoterpene that the potentially the most widely encountered terpenoid in nature. It has a distinct pine tree smell that is produced by plants as a purported insect repellent. It is said to possibly have anti-inflammatory properties.
Borneol – Borneol is a monoterpene that is said to have anti-inflammatory properties
Delta-3-Carene – Delta-3-Carene is a monoterpene described as having a musky earth and damp woodlands smell
Eucalyptol – Eucalyptol is a monoterpenoid that has a mint-like and spicy smell. Due to its pleasant smell it is sometimes used in flavoring, fragrances, and cosmetics at low levels. It is commonly added to commercial mouthwashes at low levels to produce a minty flavor. It has also been suggested to have anti-inflammatory properties.
Humulene – Humulene is a sesquiterpene that is also commonly found in hops and is described as having a “hoppy” aroma similar to the smell in the brewing process of beer.
Terpineol – Terpineol is a monoterpene alcohol that has a pleasant smell similar to that of lilacs. It is a common ingredient of perfumes, cosmetics, and flavoring at low levels.