The essential oil of pennyroyal is considered toxic. Death has been reported after consumption of small amounts. A characteristic noted in most cases of pennyroyal overdose is a strong minty smell on the patient's breath.
A possible role for N-acetylcysteine (NAC) in the management of pennyroyal overdose has been suggested. However, this application has not been confirmed by animal or human studies.
The essential oil of pennyroyal may act as an emmenagogue (menstrual flow stimulant) and induce abortion. However, it may do so at lethal or near-lethal doses, making this action unpredictable and dangerous. Future research to determine the safety and efficacy of the less toxic parts of the pennyroyal plant on the menstrual cycle is needed before a recommendation can be made.
Aloe herbal horse spray, brotherwort, chasse-puces, churchwort, Cunila pulegioides, dictamne de Virginie, European pennyroyal, fleabane, flea mint, fretillet, Hedeoma phlebitides, herbal horsespray, herbe aux puces, herbe de Saint-Laurent, Labiatae (family), la menthe pouliot (French), Lamiacea (family), Lurk-in-the-Ditch, Melissa pulegioides, mentha pouillot, Miracle Coat spray-on dog shampoo, mock pennyroyal, mosquito plant, Old World pennyroyal, pennyroyal essential oil, petit baume, piliolerial, poley, pouliot royal, pudding herb, pudding grass, pulegium, pulegium oil, Pulegium vulgare, pulioll-royall, Pulegium regium, run-by-the-ground, squaw balm, squawmint, stinking balm, tickweed.
These uses have been tested in humans or animals. Safety and effectiveness have not always been proven. Some of these conditions are potentially serious, and should be evaluated by a qualified healthcare provider.
Abortifacient (uterus contraction stimulant/abortion inducer)
Folkloric use and several human case reports describe use of the essential oil of pennyroyal to cause abortion. However, it may do so at deadly or toxic doses, making this an unpredictable and dangerous use.
Menstrual flow stimulant (emmenagogue)
Folkloric use and several human case reports describe use of the essential oil of pennyroyal as an emmenagogue (menstrual flow stimulant). However, it may do so at lethal or near-lethal doses, making this action unpredictable and dangerous.