Several retail stores are selling cinnamon to be taken as an over-the-counter health supplement. Most, if not all, food stores sell cinnamon as a spice for enhancing the flavors of food. Some of the cinnamon jars in pharmacies make no effort to tell the consumer what kind of cinnamon is in the jar.
There are several kinds of cinnamon sold in the US. True cinnamon is rarely what you get. Here true cinnamon is defined as Ceylon Cinnamon.

All cinnamon contains coumarin. The amount in many kinds of cinnamon is much higher than the amount in Ceylon Cinnamon – the lowest naturally. Coumarin is a health hazard.

I take cinnamon to help my metabolism. I also use it as a spice. I love the flavor of cinnamon. I reduced my exposure to coumarin by using Ceylon Cinnamon.

One unanswered questions is: How safe is Cinnamon when taken in large amounts?

A partial answer is that Ceylon Cinnamon is safer than other cinnamons.

You can buy non-Ceylon cinnamon with less coumarin due to a water process that removes coumarin. The producer of that cinnamon thinks you don't want to consume coumarin in any large quantity. I agree.

In researching this article I saw the information on the topic change as more information became available. The labels on some cinnamon have a disclaimer stating that the FDA has not approved or disapproved any claims for cinnamon.

Cinnamon came to my attention as I searched for ways to control my blood glucose level. Wikipedia has a helpful page on cinnamon.

In addition to helping control blood glucose levels there are other benefits to taking Ceylon Cinnamon.

Some sites state after you damage your liver you can stop taking cinnamon and your liver will heal. Of course, the assumption is your liver only has a problem with cinnamon, nothing else, and was healthy to start, not always a valid premise. For instance, an exception would be an alcoholic diabetic. There are others.

There is a credible body of data showing normal consumption of cinnamon poses very little or no health risk. I am discussing a dose in the 2+ mg range per day taken over a long period of time.

The information available today shows Ceylon Cinnamon to be safe and not toxic when your liver is OK.

A cinnamon dosage of 2+ mg per day may also help lower your lipid levels.

Ceylon cinnamon is inexpensive and worth trying to see if you lower your blood sugar level and/or lipid levels. There is no large clinical study showing conclusively it will help you. Anecdotal evidence says it will. You have little to lose and lots to gain.

Try it for yourself and monitor your blood glucose level. As mine has improved I will continue with a cinnamon bark regimen. If your level doesn't improve, stop taking it. I suggest you take cinnamon for two months and decide for yourself.

The link below is wirth checking out.