Pulegone occurs naturally in a variety of plants in the mint family. It is found in all mint extracts but is not present in natural menthol, which is isolated from mint and purified through the crystallization process.
In 2018 the FDA banned the use of synthetic Pulegone in food flavourings along with six other artificial flavouring ingredients linked to risk. [1]
The FDA banned synthetic pulegone but did not ban the natural version, which is a primary constituent of mint extracts as there were no links to cancer found with natural mint extracts.
It appeared that these natural extracts had many beneficial properties and were being used by humans in herbal medicine for hundreds of years. It is important to understand that synthetic ingredients are commonly made through petrochemical processes that can alter the properties or risk profiles of chemicals compared to their naturally occurring counterparts.
Natural peppermint and spearmint extract are still widely used by the flavouring industry in food and are still permitted by the FDA. You can see the natural composition and some research relating to peppermint and its effects at ResearchGate.net
We've heard that some mint and menthol e-liquid flavours may contain pulegone and that it is a potential carcinogenic, so should we avoid vaping Pulegone? We have to remember that the presence on its own does not cause a product to be toxic or harmful, and in toxicology - the amount makes the poison.
To give you an example, based on the calculation of traces of Pulegone in e-liquid pods, to reach an exposure level above the threshold of carcinogenic concern for Pulegone, a person would have to consume hundreds of pods per day.
Chemical Composition of Peppermint Extract
Constituent | Percent |
Limonene | 1% - 5% |
Eucalyptol | 3.5% - 14% |
Menthone | 14% - 32% |
Menthofuran | 1% - 9% |
Isomenthone | 1.5% - 10% |
Menthyl Acetate | 2.8% - 10% |
Isopulegol | Maximum of 0.2% |
Menthol | 30 - 55% |
Pulegone | Maximum of 4% |
Carvone | Maximum of 1% |
As the table above shows, Pulegone makes up at most 4% of Peppermint, which would typically be mixed into an e-liquid at 0.5-2% maximum of the complete e-liquid mixture.
The presence of Pulegone, if present; would be at roughly 0.005% of an e-liquid.
So all of you 100-pod-a-day vapers are suggested to cut back.
This post was written with the help and knowledge of Jonathan Marshall from Flavour Crafters