Out of the abundance of flora and fauna we possess on planet earth, by far one of the most unique is the cannabis plant. Arguably, the quality that makes the cannabis plant stand out most is its particular smell.
Ranging from diesel piney-ness to a bouquet of tropical fruit, cannabis never ceases to amaze us with its exotic aromatics. But, what exactly makes cannabis smell the way that it does?
This of course can be attributed to terpenes; highly volatile aromatic molecules that appear as odorous oils on the cannabis plant.  It has been argued that the true purpose of terpenes is to protect the plant from damaging insects and to act as a sort of draw for pollinators.
In addition to benefitting the cannabis plant, studies have shown that humans also benefit from terpenoids. One example being β-myrcene, which has analgesic, anti-inflammatory, anti-mutagenic, and antibiotic properties. 
The absorption of terpenes isn’t solely limited to smoking or vaporizing. Another popular method is through dermal application in the form of topicals. Before being added to a topical medium, terpenes exist in the form of essential oils. In this form, terpenes have proven to be highly penetrative in nature. 
Terpene skin absorption levels are largely dependent on the topical medium in which they are infused. For example, the terpene citronellol applied in a hydrogel successfully penetrated all dermal levels.  In comparison, the mixture of an oily solution with citronellol failed to penetrate a single layer.
As a medicinal application, terpenes can provide us with a multitude of benefits. By themselves, terpenes have proven to be highly absorbent into the skin’s dermal layers as essential oils. In addition, terpenes have been lauded for their ‘entourage effect’ which enhances the effects of THC. 
While a handful of brands such as Canna-Fusion have begun to offer terpene infused topicals, it is much more prevalent for consumers to mix their terpene essential oils with topicals. In the latter case it’s best to have the terpenes stored in a carrier oil which makes it much easier for application to the skin.
As the medicinal benefits of terpenoids continue to be uncovered one can hope to see more ‘terpene infused’ topicals on the market.
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- Russo, Ethan B. and Grotenherman, F. Handbook of Cannabis Therapeutics: From Bench to
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- Cal, K. “Skin penetration of terpenes from essential oils and topical vehicles”. Planta Med. 2006; 72(4): 311-6 [Times cited = 80 , Journal impact factor = 2.342]
- Andre, Christelle M., et al. “Cannabis sativa: The Plant of the Thousand and One Molecules”. Front Plant Sci. 2016; 7: 19 [Times cited = 172, Journal impact factor = 4.298]
Photo courtesy of Cannabis Now