It's dirt cheap, may even be in your kitchen cupboard right now! Now, you may look at this study and say, "yeah but it's done on rats". However, consider this..
There WAS a human study and the findings suggest people may be MORE sensitive than rats to cinnamon. A 40-day course of capsules containing 1, 3 or 6 g cinnamon (not an extract) reduced the test subjects' sugar and cholesterol levels. The amount they took was not important – all dosages worked equally well. One gram of cinnamon is a half a teaspoon.
The cinnamon also worked in people who didn't have diabetes A researcher tried the cinnamon out on himself and discovered that his blood sugar level went down too.
More at the jump..
https://www.ncbi.nlm.nih.gov/pubmed/14625128