Is too much cinnamon toxic?

Consuming too much cinnamon can indeed be toxic due to the presence of coumarin, a compound found in cinnamon that can be harmful at high levels. Andrew Huberman advises not to ingest more than about a teaspoon to a teaspoon and a half of cinnamon per day to avoid exceeding the threshold at which it can become problematic. While cinnamon can be beneficial for regulating blood glucose levels by slowing gastric emptying and reducing the glycemic index of foods, exceeding this daily limit can lead to toxicity related to coumarin 1.