Pennyroyal is a plant in the mint family, and is widespread in Europe and North Africa. Historically, it has been a popular cooking herb, though its use has decreased in modern times. While the pennyroyal plant has many uses, including as a pest repellent, Pennyroyal Essential Oil contains high amounts of pulegone, a compound with known health concerns. For this reason, therapeutic use of pennyroyal essential oil requires particular care, and aromatherapy use of Pennyroyal Essential Oil should be limited.
NOTE: Pennyroyal Essential Oil should not be used during pregnancy or during breastfeeding. It should not be ingested, and needs to be highly diluted (at 1% or less) if being used topically.