I've found several online studies that suggest cinnamon is a safe and effective way to lower blood sugar--but also other studies that didn't find it particularly helpful.
Just to test the theory, I bought some organic cinnamon and some vegi-caps from a health food store and made my own cinnamon capsules (about 1/4 tsp. of cinnamon per capsule, or less) and tried taking them at night. (I have impaired fasting glucose and tend to have higher morning glucose.)
It seemed to have some effect. For example, one day when I didn't take cinnamon at night, my morning reading was 113. That night, I took it before bed, and my morning glucose was 98. Looking back over several weeks, it does seem that most of my blood sugars in the 90s were after taking cinnamon, and most of those without cinnamon were in the low 100s up to about 115.
I asked my endo about this, and she said there didn't seem to be enough evidence either way. She also said that since my A1c is normal, (in the mid-5s) I shouldn't worry so much about these fluctuations. But, since I have PCOS and am at high risk for diabetes, I'm trying to keep this condition from developing into full-blown diabetes.
I wouldn't mind taking cinnamon daily, but I have also read some reports that say most cinnamon sold in the US is cassia, which can be toxic to the liver in high quantities. I don't know how much is considered too much. I have also seen cinnamon capsules that are water soluble and supposedly safer for the liver; of course, they are also more expensive.
I'm just wondering if anyone else has experimented with cinnamon, and what the effects have been--positive or negative. Would love to hear any personal experiences or pertinent studies!