Cinnamon Bark has a rich history.  it was listed in Europe's first authorative guide to medicines, Dioscorides" de Materia Medica, that became the standard reference work for herbal treatments and healing for over 1,700 years. 

Cinnamon is part of the "Four Thieves Vinegar" (also called Marseilles Vinegar) used by the 15th century grave-robbers to protect themselves from the black plague.

Cinnamon is widely used for a variety of conditions due to its medical properties of:
anti-inflammation (a natural COX2 inhibitor), powerfully antibacterial, antiviral, antifungal, anticoagulant, circulatory stimulant, stomach protectant (perhaps for ulcers), and anti-parasitic properties (worm expeller).

This oil feels hot and should always be diluted.  It can irritate nasal passages if directly inhaled from diffuser or bottle. May be used in cooking and for flavoring beverages