Pennyroyal oil (Mentha pulegium)

Tier 4 — risky / avoid · Abortifacient · Hepatotoxicity · Fatal

Contains pulegone, which the body converts into a liver-toxic compound through normal metabolism. Multiple documented deaths from oral ingestion have been reported, with lethal doses as low as 10 mL of the essential oil. Historically misused as an herbal remedy. No therapeutic benefit whatsoever. There is no safe dose for internal use.

Dose: AVOID — lethal at doses as low as 10 mL of essential oil