Mint can cause digestive issues such as vomiting and diarrhea in cats.
Some types of mint, like pennyroyal, are toxic to cats and can cause liver damage.
Suggestions
It is best to avoid giving mint to cats.
If you suspect your cat has ingested mint and is showing signs of distress, contact your veterinarian immediately.
Note: even if labeled as safe, any food can potentially cause allergies. When introducing a new food, please feed a small amount and observe your cat for any allergic reactions.