Common Use
Fleas (topical) (potential toxicity)
Pennyroyal oil, made from the Mentha pulegium plant, is often recommended as a topical application for the control of external parasites, particularly fleas.
Pennyroyal oil has been used successfully as a natural flea treatment. However, the oil is quite potent and can cause illness and death. Safer alternative flea control measures are available.
While properly diluted pennyroyal oil has been used safely, due to potential toxicity and death if used improperly, it is not generally recommended as a natural form of flea control.