Humulene: An Earthy and Soothing Cannabis Terpene

Humulene doesn’t just add flavours of earth, wood, and spice to certain cannabis strains. The compound also targets the CB1 receptors of the endocannabinoid system—the same network that underpins the cannabis high. Learn everything you need to know about this fascinating compound below, including the latest scientific research.

What Are Terpenes, Exactly?

Terpenes are aromatic compounds that underpin the flavours and aromas of different plants and their anatomical parts. These fragrant chemicals are rooted in the unmistakable tastes of mango and apple and the aromas of mint, pine, and orange. Around 30,000 known terpenes exist in nature across several distinct molecular groups. While structurally different, these compounds share the same building blocks—isoprene units.

Isoprene units are building blocks that enable plants to manufacture various constituents, including essential oils, pigments, and hormones. Terpenes are categorised based on the number of isoprene units they contain. Simple monoterpenes such as limonene and myrcene contain just two isoprene units. In contrast, more complex sesquiterpenes, such as humulene beta-caryophyllene, contain three. Elsewhere in nature, large polyterpenes contain over forty isoprene units.

Aside from smelling and tasting, terpenes play an essential role in the health and survival of many plant species, including cannabis.

The Role of Terpenes in Nature

As secondary metabolites, terpenes aren’t directly involved in the growth and reproduction of cannabis plants. You can look at them more like chemical weapons and shields. Weed plants invest resources into creating terpenes to help manage stress and increase their chances of survival. Volatile in nature, terpenes are able to defend plants against a range of pests. Terpenes such as humulene, pinene, and eugenol are directly toxic to some pests, whereas the likes of limonene can repel and deter aphids from laying eggs. Other terpenes act as growth inhibitors and influence the development of certain pest species.

Terpenes also help to shield plants from abiotic or nonliving sources of stress. The production of these phytochemicals offers a line of defence against fluctuations in temperature, drought, and UV radiation from the sun.

Plants also use terpenes to impact their environment. These chemicals act as signalling molecules between plants that enable them to alert each other to predators and pests, giving their neighbours a chance to ramp up the production of more defensive compounds. Certain tree species also emit higher levels of terpenes into the atmosphere, impacting weather patterns.

A-Pinene

Anti-inflamatoire
Aids Memory
Anti-bacterial
Bronchodilator

Also found in
pine needles

Linalool

Anesthetic
Anti-convulsant
Anti-anxiety
Analgesic

Also found in
lavander

Beta-CaryophYllene

Anti-inflamatory
Analgesic
Protects cells lining the
digestive tract

Also found in
black pepper

Myrcene

Sedative Effect
of strong Indicas
Sleep Aid
Muscle Relaxant

Also found in
in hops

Limonene

Treats Acid Reflux
Anti-anxiety
Antidepressant

Also found in
in citrus

A-Pinene

Anti-inflamatory
Bronchodilator
Aids Memory
Anti-bacterial

Also found in pine needles

Linalool

Anesthetic
Anti-convulsant
Analgesic
Anti-anxiety

Also found in lavander

Beta-Caryophillene

Anti-inflamatory
Analgesic
Protects Cells Lining the Digestive Tract

Also found in black pepper

Myrcene

Contributes to Sedative Effect of Strong Indicas
Sleep Aid
Muscle Relaxant

Also found in hops

Limonene

Treats Acid Reflux
Anti-anxiety
Antidepressant

Also found in citrus

The Chemistry of Humulene

Cannabis plants produce upwards of 150 unique terpenes. Among these, a handful stand above the rest. These compounds are more valuable to consumers because of their preferred flavours and aromas and have, therefore, received more attention from scientific researchers. Humulene, also known as alpha-humulene, has become particularly popular owing to its pleasant earth aromas and soothing properties.

Humulene, with a chemical formula of C15H24, comprises three isoprene units. It is classified as a sesquiterpene alongside beta-caryophyllene. The additional isoprene unit that sets it apart from monoterpenes makes this molecule larger and more stable, meaning it is less volatile than terpenes such as pinene.

How Is Humulene Extracted?

Humulene has very low water solubility in its natural form. Many manufacturers use steam distillation to extract humulene and other terpenes from plant material. This process uses hot steam to vaporise terpenes before condensing them into a liquid solution. The oily terpenes sit atop the water, making them easier to separate and isolate.

Where to Find Humulene

Humulene occurs in a range of different plants, including:

• Cannabis
• Hops
• Black pepper
• Ginseng
• Basil
• Tobacco
• Sage
• Ginger

In some plants, such as pine trees, sage, and ginger, the terpene occurs in various tissues. However, in the case of cannabis and hops, it’s produced in specialised glands called trichomes. Both cannabis trichomes and the lupulin glands of hops biosynthesis humulene and churn it out (alongside over phytochemicals) as a viscous resin.

The Aroma and Taste of Humulene Terpene

Humulene features a distinctive flavour and aroma that is popular among many cannabis users. This terpene infuses buds with savoury hints of earth, wood, herbs, spices, and hops. These flavours are apparent when smoking but really stand out during vaporisation. These tastes also make humulene-rich strains preferable to cannabis chefs when cooking up infused savoury dishes.

Humulene Effects: What to Expect

Strains high in humulene vary in their effects depending on other phytochemicals present. Each variety features a complex cocktail of compounds, with humulene playing an important role. Whether a cultivar is high in THC or CBD, humulene adds a soothing and physically relaxing effect.

Humulene: A Look at the Research

While the effects of humulene on the human body remain relatively unknown, a selection of cell and animal studies have revealed its potential mechanisms of action. Check out some of the studies below to see how scientists could use the terpene in the future.

Humulene: A Powerhouse Cannabis Compound

Humulene contributes pleasant earth, wood, and spice flavours to many cannabis strains. On top of this, it also impacts the subjective effects of these varieties, imparting a relaxing and soothing sensation. Ongoing investigations are probing the compound's potential role in various diseases, including bacterial infections, tumours, and parasites. While the research remains far too early to draw any conclusions, we could see humulene gain a lot more focus in medical marijuana programs as more human studies emerge in the future.