Cassia is the common cinnamon you find in most spice aisles. It has a stronger, spicier kick than the pricier Ceylon variety. This type packs more coumarin, a natural plant compound. People take it as a powder mixed into food or drinks, or as a capsule, often right with meals to help with digestion and the body's sugar metabolism. It also supplies general antioxidant support.
Stick to ordinary cooking amounts or moderate capsule doses. Because of the coumarin, heavy long-term use could stress the liver.