Pennyroyal

Background

A creeping mint with a strong camphor-minty smell. Historically known as a flea repellent (pulex means flea in Latin) and a folk herb.

Insect repellent, digestive, and emmenagogue. The last is why it became dangerous.

Traditionally used against fleas and ants. Safer modern alternatives exist (peppermint, lavender, citronella, cedarwood).

Almost never used because of safety concerns.