Limonene is one of many different terpenes found within various plants, insects and essential oils.

Terpenes are aromatic oils and compounds that give fruits, plants, and some varieties of insects their unique aroma and smell.

In nature, these compounds have several purposes,  including attracting or repelling predators or pollinators, aiding in reproduction, and providing protection against the elements.

Within cannabis, myrcene is one of the most abundant terpenes out of more than 150 different varieties, providing cannabis strains with their unique aroma, flavour and supposed effects. Terpenes are a critical component of consuming cannabis, but not many know what they are, where they come from, or their reported effects.

This article is part of a series on cannabis terpenes and is designed to highlight one of cannabis’ most fragrant terpenes, limonene.

What is Limonene?

Limonene is a naturally occurring monoterpene, a class of terpenes that serves as building blocks for other terpenes. In cannabis, crystal-like structures known as glandular trichomes are responsible for terpene production.

Aside from appearing in cannabis, limonene is found in fruits and vegetables around the world. Notable examples include lemons, limes and other citrus fruits. While limonene is primarily found within citrus fruit and its rinds, it can also be found within peppermint, rosemary and juniper.

Limonene has a fresh, lemon-like aroma, making it a popular addition to many foods, beverages and cleaning products. Many household cleaners will incorporate this terpene in their formulas to give off a fresh, citrus scent when used.

In plants, its strong aroma has made it an effective and eco-friendly insect repellent. Within cannabis, limonene is found in high volumes in comparison to other terpenes, making it one of the most abundant.

In addition to providing different cannabis strains with their unique aroma and flavour profile, studies suggest that terpenes can exhibit some pharmacological effects.

When combined with other terpenes and THC and CBD, a reaction known as the entourage effect may promote relaxation, stress relief, and other psychoactive effects. The entourage effect has some scientific basis backing for it, but research regarding its effects is inconclusive.

What are the Reported Effects of Limonene?

In the plant kingdom, limonene is used as an effective repellent against insects and other pests.

Anecdotally, limonene has many therapeutic benefits. Its pleasant and calming aroma has been said to improve digestion, alleviate anxiety and aid in weight loss. This terpene is also believed to be able to combat high blood pressure and inflammation. However, these claims are unsubstantiated by science, except in rodent trials.

In a 2019 study conducted on rats, researchers found that limonene had anti-arrhythmic properties when treating rats with hypertension. They conclude that this terpene could be a promising substance in the treatment of cardiovascular diseases.

Another study published in 2006 tested limonene’s effect on anxiety through vapour with high levels of limonene. When the vapour was inhaled, serotonin and dopamine levels within the mice, neurotransmitters that are linked to mood, were elevated.

The data suggest that high doses of limonene may have antidepressant-like effects and alleviate anxiety, but it’s unclear how limonene is able to achieve this and whether or not these results translate over to humans.

In an earlier study conducted in 2013, limonene was orally administered to rats to investigate its anti-inflammatory effects. The study demonstrated significant anti-inflammatory effects and suggests that limonene may be used as a diet supplement to reduce inflammation.

Despite these promising results, more research is needed before anything conclusive can be said about this terpene’s therapeutic human benefits.

More Than Just Lemons

Limonene occurs naturally in citrus fruits, plants and cannabis and is just one of many terpenes influencing the flavour and aroma of our favourite cannabis strains. Producing a fresh, fragrant and invigorating aroma, you can find this terpene as a major component in many indica and sativa strains available today.

However, as with the supposed differences and effects that indica and sativa strains can deliver, more research is needed before scientists can say anything certain about the effects of limonene as a terpene. 

Please note that this content on limonene and terpenes is intended to act as entertainment and a general educative aid and is not intended to act as or substitute healthcare advice from a professional healthcare service or qualified healthcare provider. If you have any questions or concerns, please consult your physician or a qualified healthcare provider.