Pet Safety / Compounds / Pennyroyal oil (Mentha pulegium)

Is Pennyroyal oil (Mentha pulegium) safe for dogs and cats?

Severe risk for dogs

Not veterinary or professional safety advice, and not a substitute for a veterinarian — consult one about your animal. Full disclaimer →

Pennyroyal flea treatments have killed dogs; hepatotoxic at low doses in small animals

What is pennyroyal oil (mentha pulegium)?

CAS number: 8007-44-1

Risk for dogs

Severe risk

Pennyroyal flea treatments have killed dogs; hepatotoxic at low doses in small animals

Regulatory consensus

1 regulatory body has classified Pennyroyal oil (Mentha pulegium).

Agency	Year	Classification	Notes
EDC Assessment	—	Suspected endocrine disruptor

Where pets encounter pennyroyal oil (mentha pulegium)

Personal Care — essential oil (historical), aromatherapy (AVOID)

Safer alternatives

Lower-risk approaches that achieve a similar outcome to Pennyroyal oil (Mentha pulegium):

Avoidance (no chemical substitute)
Trade-offs: Direct chemical substitution requires verification that the replacement does not introduce new hazards (regrettable substitution). Conduct full hazard assessment of proposed alternative before adoption.

Relative cost: 1.2-2×

Frequently asked questions

Is pennyroyal oil (mentha pulegium) safe for pets?

Pennyroyal flea treatments have killed dogs; hepatotoxic at low doses in small animals

What products contain pennyroyal oil (mentha pulegium)?

Pennyroyal oil (Mentha pulegium) appears in: essential oil (historical) (Personal care); aromatherapy (AVOID) (Personal care).

See Pennyroyal oil (Mentha pulegium) in the pets app

Look up products containing pennyroyal oil (mentha pulegium), compare to alternatives, and explore the full data record.

Open in pets View raw API data

Sources (1)

PubChem Compound Database (2026) — database

Reference data, not professional advice. Aggregates publicly available regulatory and scientific data; not a substitute for veterinary, medical, legal, or regulatory advice. Why we built ALETHEIA →