Peppermint possesses mild toxicity to humans, cats, and dogs. Consumption of any part of the plant leads to symptoms like gastrointestinal distress, dizziness, muscle weakness, vomiting, diarrhea, and central nervous system depression due to compounds such as pulegone, menthone, menthol, and menthofuran. Moderation is crucial in culinary use, and immediate veterinary care is recommended for pets.