The majority of the aromas we associate with plants are the result of terpenes and flavonoids. Human beings can smell and taste these compounds but this is not the only way they affect us.

Aromatherapy uses different essential oils to regulate mood, and sleep habits and for curative purposes.

More than 100 terpenes have been identified in marihuana but there are actually many more when you take into account the multiple variations of each terpene.

The age, maturity, and the timing of the harvest can all affect the number of terpenes and possibly also the proportion.

Below we identify the terpenes most typically found in marihuana and describe each in descending order of abundance.

Myrcene is the most plentiful terpene in almost all strains of marihuana but is not found in hemp. It is also found in large quantities in hops, in lemon leaves, in cane sugar, and in Myrcia, the plant after which it is named.

Its smell is described as like cloves, earthy, green vegetation, fruity like tropical mango with hints of mint. All these are commonly used to describe the smell of cannabis.

Myrcene is an effective analgesic, anti-inflammatory, and antibiotic. It is possible that myrcene has a synergistic effect on THC so that a stronger experience is felt when the two molecules act together. This is probably because they alter the permeability of the cellular membrane, allowing more THC to reach the brain.

Limonene can be found in lemon peel and many other flowers and fruits and is one of the most abundant terpenes in cannabis resin.

Limonene has anti-bacterial, fungicidal, and anti-carcinogenic properties. Limonene aerosols are used to fight depression.

Owing to these fungicidal and anti-carcinogenic properties, it is believed that limonene protects against Aspergillus, a carcinogenic mold found in cannabis smoke.

Plants use limonene to repel predators.

Caryophyllene is the terpene found in black pepper (15-25%), cloves (15-25%), and cotton (15-25%) as well as many other herbs and spices in smaller quantities. It smells like sweet, dry cloves and is reminiscent of timber with a camphor base and astringent lemon. It enhances the spicy taste of pepper and its oil is used to strengthen the taste of tobacco.

It has analgesic properties and is one of the active ingredients of clove oil, which is used to treat toothache.

Pinene is the aroma typically associated with pine and its resins. It is the major component of turpentine and is found in many other oils in appreciable quantities such as rosemary, sage, and eucalyptus.

Pinene is used medicinally as an expectorant and an antiseptic. It is also a bronchodilator; the smoke seems to expand in your lungs and the high is very rapidly owing to the high percentage of the substance passing into the bloodstream and onto the brain. It also improves our ability to focus, enhances our self-esteem, and boosts energy levels.

Pinene is probably what gives skunk strains their penetrating aroma.

Terpineol is present in lily, citrus, apple, and lime. A minor constituent in many plant oils, its fragrance is used in perfumes and soap.

Terpineol is obtained commercially by processing other terpenes. It reduces mobility by 45% in experiments conducted on mice, which may explain couch-lock syndrome although this aroma is not associated with profound body stones.

Terpineol is found in cannabis strains with high concentrations of pinene and its smell is masked by the spicy, woody odor of the latter.

Borneol smells like the mentholated odor of camphor and can easily be converted into it. It is found in small quantities in many types of oil and is derived commercially from artemisia plants such as wormwood or some species of cinnamon.

Used as a sedative in ancient Chinese medicine and recommended to treat fatigue, and stress and to get over viral infections.

The camphor tones of Silver Haze strains are unmistakable and the effect is relaxing with psychedelic aspects. This indicates the presence of large quantities of borneol.

Delta 3-Carene has a penetrating sweet odor, is a constituent of cedar and pine resin and is found in many plants such as rosemary. In aromatherapy, cypress oil, which has a high Delta 3-Carene content, is used to dry fluids, tears, blocked-up noses, and heavy menstrual flow. It may explain why you sometimes get a dry mouth and dry eyes when you smoke marihuana.

Linalol has a floral essence that is reminiscent of spring flowers such as lily but slightly spicier. It is refined from lavender, neroli, and other essential oils.

Linalol is being trialed to treat serious cancer cases and is also a component of sedative oils.

Pulegone has a mentholated odor of camphor and has been used in the confectionery industry. Heavy consumption can cause liver damage though only small quantities are found in marihuana.

It is a cholinesterase inhibitor, which means it blocks the protein that destroys acetylcholine, which is used by the brain to store memory. As such, it can counter the activity of THC as this foes reduce acetylcholine levels.

1,8-Cineole is the main component of eucalyptus oil and has a mentholated aroma of camphor. It is also found in other aromatic plants and in small quantities in marihuana. Used to improve circulation and to relieve pain, it also has other topical uses.

Cineole easily crosses the cerebral barrier and causes a very rapid effect. Eucalyptus oil is believed to be a stimulant and gives balance. It may be what gives marihuana its stimulating and creative properties.

Terpenes, their interaction with each other, and the resulting effect on cerebral activity, is a fascinating subject and another level of exploration and source of creativity for breeders. Understanding terpenes can help us predict what each contributes to the mental effect of the weed we smoke.