Cinnamon has also been shown to fight the bacteria that causes most ulcers. Test-tube studies have found that other substances in the essential oil, diterpenes, may help reduce allergies. The German Commission E suggests taking 2-4 grams of cinnamon powder daily. No more than a few drops of essential cinnamon oil should be taken per day, and then only for a few days at a time. Some practitioners also recommend 2-3 ml of cinnamon tincture three times per day.
Many stores also sell cinnamon oil and cinnamon tinctures.
Chronic use of cinnamon may cause inflammation in the mouth. The German Commission E does not recommend cinnamon for use by pregnant and lactating women. At this time, there are no well-known drug interactions with cinnamon. Akira T, Tanaka S, Tabata M. Pharmacological studies on the antiulcerogenic activity of Chinese cinnamon. A novel inhibitor of bacterial endotoxin derived from cinnamon bark.