Pet Safety / Compounds / Pennyroyal oil (Mentha pulegium)

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

Severe risk for pets

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 bodyhas classified Pennyroyal oil (Mentha pulegium).

AgencyYearClassificationNotes
EDC Assessment—Suspected endocrine disruptor

Regulators apply different standards of evidence — animal-data weighting, exposure-pattern assumptions, epidemiological power thresholds — which is why two scientific bodies can review the same data and reach different conclusions. The disagreement is the data.

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)
  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 →