Terpenes, or terpenoids, are the compounds in cannabis that give the plant its unique smell. THC/CBD and the other cannabinoids have no odor, so marijuana’s compelling fragrance depends on which terpenes predominate. It’s the combination of terpenoids and THC/CBD that endows each strain with a specific psychoactive flavor.
Typically, terpenes are volatile molecules that evaporate easily and readily announce themselves to the nose. Therein lies the basis of aromatherapy, a popular alternative-healing modality. Like their odourless cannabinoid cousins, terpenes are oily compounds secreted in the marijuana plant’s glandular trichomes. Terpenes and THC share a biochemical precursor, geranyl pyrophosphate, which develops into the cannabinoids and terpenoids that saturate the plant’s flower tops.
The terpenes in marijuana have given the plant an enduring evolutionary advantage. Some of these essential oils are pungent enough to repel insects and animal grazers; others prevent fungus. To combat plant disease and infestation, organic pot growers spray the terpene-rich essential oils of neem and rosemary onto their crops. And terpenes, it turns out, are healthy for people as well, according to a September 2011 report by Dr. Ethan Russo in the British Journal of Pharmacology that discussed the wide-ranging therapeutic attributes of terpenoids, including several aromatic compounds that figure prominently in cannabis strains.
MOST COMMON TERPENE PROFILES IN CANNABIS:
- Alpha-pinene (essential pine oil), the most common terpene in the plant world and one often found in cannabis, is a bronchodilator potentially helpful for asthmatics. Pinene also promotes alertness and memory retention by inhibiting the metabolic breakdown of acetylcholinesterase, a neurotransmitter in the brain that stimulates these cognitive effects.
- Myrcene, another terpene present in numerous cannabis varietals, is a sedative, a muscle relaxant, a hypnotic, an analgesic (painkiller) and an anti-inflammatory compound. This musky terpene contributes mightily to the infamous “couch-lock” experience, Russo maintains.
- Limonene, a major terpene in citrus as well as in cannabis, has been used clinically to dissolve gallstones, improve mood and relieve heartburn and gastrointestinal reflux. Limonene, an anticonvulsant, has been shown to destroy breast-cancer cells in lab experiments, and its powerful antimicrobial action can kill pathogenic bacteria. (Lemon Kush, anyone?)
- Linalool, a terpenoid prominent in lavender as well as in some cannabis strains, is an anxiolytic compound that counters anxiety and mediates stress. In addition, linalool is a strong anticonvulsant, and it also amplifies serotonin-receptor transmission, conferring an antidepressant effect. Applied topically, linalool can heal acne and skin burns without scarring.
- Beta-caryophyllene is a sesquiterpene found in the essential oils of black pepper, oregano and other edible herbs, as well as in cannabis and many green, leafy vegetables. It is gastro-protective, good for treating certain ulcers, and shows great promise as a therapeutic compound for inflammatory conditions and autoimmune disorders because of its ability to bind directly to the peripheral cannabinoid receptor known as CB2.
In the future, when Cannabis is fully legal nationwide, it should be possible to access strain-specific cannabis oils, as well as made-to-order marijuana extracts with a full array of terpenes artfully tailored to meet the needs and desires of individual users.