Short answer
Any amount of garlic powder is concerning because it's a concentrated form of allium toxin. Even a small lick can be dangerous for a cat, as their systems are highly sensitive. Toxicity depends on your cat's weight and the amount ingested, but because it's so potent, we don't advise waiting to see signs. Symptoms like vomiting, weakness, and pale gums may take a day or two to appear. If you suspect any ingestion, call the ASPCA Animal Poison Control Center at 888-426-4435 or your emergency vet immediately for guidance.
Garlic powder — Food safety facts
Do not feed · Cats · full breakdown on the linked food page
Concentrated allium — far more dangerous gram for gram than fresh garlic.
The full verdict, portion guidance and serving notes are collected on the Garlic powder food facts page.