Hi Bushan, I know Healthline has an article on this, which I’ve linked in this message. The Saigon, also known as Vietnamese cinnamon (as Scott Wilson have put out in one of his comment threads) contains high amounts of coumarin, which makes over-consumption quite dangerous. In that sense, the Saigon is a lot closer to the Cassia than the Ceylon. You can read the rest of the details here.