Isopulegol is a terpene present in cannabis, distinctive for its potent minty aroma and taste. Isopulegol is the chemical precursor to menthol and is also found in lemongrass and geranium. Some potential health benefits of isopulegol include anti-inflammatory, gastroprotective and antiviral effects.
What is isopulegol?
Natural menthol that contains isopulegol is produced by freezing peppermint oil, an essential oil used as an alternative treatment for headaches. India and China are the world's two largest producers of menthol, with Germany and the United States not far behind. Outside of menthol production, isopulegol is found in the flowering geranium plant that grows in abundance in the Mediterranean and other temperate climates. Isopulegol is also found in lemongrass, along with other terpenes such as citronellol and myrcene.
Isopulegol in everyday life
Because of its cooling, mint-like properties, isopulegol is a common additive in cosmetics, soaps, and other scented personal care products. Because isopulegol is a chemical precursor to menthol, it is likely to appear alongside menthol and citronellol in natural health and beauty products (products with ingredients that are made with plant-based essential oils).
Therapeutic properties of isopulegol
Compared to other naturally-derived terpenes, little is known about the medicinal properties of isopulegol. However, some scientific studies have investigated the potential of isopulegol to fight inflammation, anxiety, and other disorders.
Isopulegol is a major component in the essential oil from the leaves of Melissa officinalis L. (Lamiacaea), or lemon balm; a plant that has long been used in traditional Moroccan medicine. A 2013 study published in the journal Advances in Pharmacological Sciences assessed the ability of Melissa officinalis oil to fight inflammation. The oil, which contained 22% isopulegol, dramatically reduced swelling in animals, which suggests that it could be a useful tool for fighting inflammation.
One German study from 2009 on gastric ulcer models in mice found that isopulegol produced notable gastroprotective effects. The researchers concluded that the terpene may also possess antioxidant properties.
Isopulegol has been tested for its antiviral properties, and one English in vitro study published in 2018 revealed that the terpene could be highly effective against the H1N1 and H1N2 strains of the influenza virus, especially during the virus's early stages.
A 2007 study conducted by Brazilian researchers indicated that isopulegol produces effects similar to anti-anxiety medications in rodents. However, it also made some depression-like behaviors worse. Although cannabis is commonly used to alleviate anxiety in people, it is unknown how isopulegol contributes to this effect; more research is needed.
By acting, in part, as an antioxidant, isopulegol has shown promise as an anticonvulsant in animal models of seizure. Several other cannabinoids and terpenes found in cannabis have demonstrable anticonvulsant properties; the combined actions of these molecules may very well contribute to the ensemble effect, when it comes to treating epilepsy.
Role of isopulegol in cannabis
Kosher Tangie is a type of cannabis that has higher-than-average levels of isopulegol, but isopulegol is not a common terpene that turns up on certificates of analysis from analytical laboratories as one of the most prominent. Much is still unknown about isopulegol's role in cannabis and its impact on resulting effects.
Releasing the cooling essence of mint, isopulegol may offer hope to fight inflammation, gastrointestinal conditions and the flu.
Major contributions from Dr. Adie Rae.