Cinnamaldehyde is one of the active compounds found in cinnamon. It was reported that cinnamaldehyde has anti-diabetic, anti-cancer, antimicrobial and anti-inflammatiry activity. Cinnamon is a common prescription compound in traditional Chinese medicine and it is used as a dietary supplement all over the world. Cinnamon dietary supplement Cinnamonforce (min. 35% cinnamaldehyde) was tested in phase II clinical trials and demonstrated therapeutic activity in patients with type 2 diabetes. The mechanism of cinnamaldehyde possibly involves the activation of PPAR gamma/delta receptors. Cinnamaldehyde is partially metabolized into cinnamic acid in the stomach and small intestine, and is almost completely metabolized into cinnamic acid in the liver. Cinnamic acid is believed to be the active metabolite, which is responsible for anti-diabetic properties of cinnamaldehyde.