Active Ingredient American Pennyroyal (hedeoma Pulegioides L.), European Pennyroyal (mentha Pulegium L.)

the essential oil of pennyroyal is considered toxic. death has been reported after the consumption of small amounts. a characteristic noted in most cases of pennyroyal overdose is a strong minty smell on the patient's breath.

Source:

medlineplus herbs and supplements: american pennyroyal (hedeoma pulegioides l.), european pennyroyal (mentha pulegium l.)

Medical Condition	Uses based on scientific evidence	Grade*
legally unspecified abortion without mention of complication	folkloric use and several human case reports describe the 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.	c

*Key to grades
A: Strong scientific evidence for this use;
B: Good scientific evidence for this use;
C: Unclear scientific evidence for this use;
D: Fair scientific evidence against this use;
F: Strong scientific evidence against this use.